# -*- coding: utf-8 -*- # ------------------------------------------------------------------------------ # Name: chord.py # Purpose: Chord representation and utilities # # Authors: Michael Scott Asato Cuthbert # Christopher Ariza # # Copyright: Copyright © 2009-2024 Michael Scott Asato Cuthbert # License: BSD, see license.txt # ------------------------------------------------------------------------------ ''' This module defines the Chord object, a subclass of :class:`~music21.note.GeneralNote` as well as other methods, functions, and objects related to chords. ''' from __future__ import annotations __all__ = ['tools', 'tables', 'Chord', 'ChordException', 'fromIntervalVector', 'fromForteClass'] from collections.abc import Iterable, Sequence import copy import typing as t from typing import overload # pycharm bug import unittest from music21 import beam from music21 import common from music21.common.decorators import cacheMethod from music21 import derivation from music21.duration import Duration from music21 import environment from music21 import exceptions21 from music21 import interval from music21 import note from music21 import pitch from music21 import tie from music21 import volume from music21.chord import tables from music21.chord import tools if t.TYPE_CHECKING: from music21 import stream from music21.style import Style environLocal = environment.Environment('chord') _ChordBaseType = t.TypeVar('_ChordBaseType', bound='music21.chord.ChordBase') _ChordType = t.TypeVar('_ChordType', bound='music21.chord.Chord') # ------------------------------------------------------------------------------ class ChordException(exceptions21.Music21Exception): pass # ------------------------------------------------------------------------------ class ChordBase(note.NotRest): ''' A base class for NotRest objects that have multiple underlying structures like notes or unpitched percussion. As of Version 7, ChordBase lies between Chord and NotRest in the music21 hierarchy, so that features can be shared with PercussionChord. >>> cb = chord.ChordBase('C4 E4 G4') >>> cb.notes (, , ) **Equality** Equality on ChordBase is strange, but necessary to help Chord and PercussionChord do meaningful equality checks themselves. Two ChordBase objects are equal if they pass all `super()` equality tests and the **number** of stored Notes are the same. >>> cb1 = chord.ChordBase('C4 E4 G4') >>> cb2 = chord.ChordBase('C4 E4') >>> cb1 == cb2 False This is surprising, but it's necessary to make checking equality of Chord objects and PercussionChord objects themselves easier. >>> cb3 = chord.ChordBase('A#4 A#4 A#4') >>> cb1 == cb3 True ''' isNote = False isRest = False _DOC_ATTR: dict[str, str] = { 'isNote': ''' Boolean read-only value describing if this GeneralNote object is a Note. Is False''', 'isRest': r''' Boolean read-only value describing if this GeneralNote object is a Rest. Is False >>> c = chord.Chord() >>> c.isRest False ''', 'beams': 'A :class:`music21.beam.Beams` object.', } # update inherited _DOC_ATTR dictionary _DOC_ATTR.update(note.NotRest._DOC_ATTR) def __init__(self, notes: t.Union[None, str, Sequence[str], Sequence[pitch.Pitch], Sequence[ChordBase], Sequence[note.NotRest], Sequence[int]] = None, **keywords): if notes is None: notes = [] if isinstance(notes, str): if ' ' in notes: notes = notes.split() else: notes = [notes] # the list of pitch objects is managed by a property; this permits # only updating the _chordTablesAddress when ".pitches" has changed self._overrides: dict[str, t.Any] = {} self._notes: list[note.NotRest] = [] # here, pitch and duration data is extracted from notes # if provided. super().__init__(**keywords) # Normally, we inherit Duration object from GeneralNote # It is overridden here in case no chord duration is specified if not any(k in keywords for k in ('duration', 'type', 'quarterLength')): self._add_core_or_init(notes, useDuration=None) else: self._add_core_or_init(notes, useDuration=self.duration) def __eq__(self, other): if not super().__eq__(other): return False if len(self.notes) != len(other.notes): return False return True def __hash__(self): return super().__hash__() def __deepcopy__(self: _ChordBaseType, memo=None) -> _ChordBaseType: ''' As Chord objects have one or more Volume, objects, and Volume objects store weak refs to the client object, need to specialize deepcopy handling depending on if the chord has its own volume object. ''' # environLocal.printDebug(['calling NotRest.__deepcopy__', self]) # as this inherits from NotRest, can use that __deepcopy__ as basis # that looks only to _volume to see if it is not None; with a # Chord, _volume will always be None new = super().__deepcopy__(memo=memo) # after copying, if a Volume exists, it is linked to the old object # look at _volume so as not to create object if not already there # noinspection PyProtectedMember for n in new._notes: n._chordAttached = new # if .volume is called, a new Volume obj will be created if n.hasVolumeInformation(): n.volume.client = new # update with new instance return new # TODO: __getitem__ def __iter__(self): return iter(self._notes) def __len__(self): ''' Return the length of components in the chord. >>> c = chord.Chord(['c', 'e', 'g']) >>> len(c) 3 ''' return len(self._notes) def _add_core_or_init(self, notes, *, useDuration: None|t.Literal[False]|Duration = None): ''' This is the private append method called by .add and called by __init__. It differs from the public method in that a duration object can be passed in which is used for the first note of the chord or as many pitches as can use it -- it's all an optimization step to create as few duration objects as is necessary. Does not clear any caches. Also requires that notes be iterable. Changed in v9: incorrect arguments raise TypeError ''' # quickDuration specifies whether the duration object for the chord # should be taken from the first note of the list. quickDuration = False if useDuration is None: useDuration = self.duration quickDuration = True newNote: note.NotRest for n in notes: if isinstance(n, pitch.Pitch): # assign pitch to a new Note if useDuration: # not False or None newNote = note.Note(n, duration=useDuration) else: newNote = note.Note(n) self._notes.append(newNote) # self._notes.append({'pitch':n}) elif isinstance(n, ChordBase): for newNote in n._notes: self._notes.append(copy.deepcopy(newNote)) if quickDuration: self.duration = n.duration useDuration = None quickDuration = False elif isinstance(n, note.NotRest): self._notes.append(n) if quickDuration: self.duration = n.duration useDuration = None quickDuration = False elif isinstance(n, (str, int)): if useDuration: self._notes.append(note.Note(n, duration=useDuration)) else: self._notes.append(note.Note(n)) # self._notes.append({'pitch':music21.pitch.Pitch(n)}) else: raise TypeError(f'Could not process input argument {n}') for n in self._notes: # noinspection PyProtectedMember n._chordAttached = self return useDuration def add( self, notes, ) -> None: ''' Add a Note, Pitch, the `.notes` of another chord, or string representing a Pitch, or a list of any-of-the-above types to a Chord or PercussionChord. Does no sorting. That is on the Chord object. >>> c = chord.Chord('C4 E4 G4') >>> c.add('B3') >>> c >>> c.duration >>> c.add('A2', runSort=False) >>> c >>> c.add(['B5', 'C6']) >>> c >>> c.add(pitch.Pitch('D6')) >>> c >>> n = note.Note('E6') >>> n.duration.type = 'half' >>> c.add(n) >>> c >>> c.duration >>> c[-1] >>> c[-1].duration ''' if not common.isIterable(notes): notes = [notes] self._add_core_or_init(notes, useDuration=False) self.clearCache() def remove(self, removeItem): ''' Removes a note or pitch from the chord. Must be a pitch equal to a pitch in the chord or a string specifying the pitch name with octave or a note from a chord. If not found, raises a ValueError >>> c = chord.Chord('C4 E4 G4') >>> c.remove('E4') >>> c >>> c.remove('D5') Traceback (most recent call last): ValueError: Chord.remove(x), x not in chord >>> c = chord.Chord('C4 E4 G4') >>> c.remove(pitch.Pitch('E4')) >>> c >>> c.remove(pitch.Pitch('F#5')) Traceback (most recent call last): ValueError: Chord.remove(x), x not in chord The Note also does not need to be the exact note of the chord, just matches on equality >>> c = chord.Chord('C4 E4 G4') >>> c.remove(note.Note('E4')) >>> c >>> c.remove(c[1]) >>> c >>> c.remove(note.Note('B-2')) Traceback (most recent call last): ValueError: Chord.remove(x), x not in chord >>> c.remove(4) Traceback (most recent call last): ValueError: Cannot remove 4 from a chord; try a Pitch or Note object Like Python's list object, the remove method of chord does not take a list of strings. >>> c = chord.Chord('C4 E4 G4') >>> c.remove(['C4', 'E4']) Traceback (most recent call last): ValueError: Cannot remove ['C4', 'E4'] from a chord; try a Pitch or Note object ''' if isinstance(removeItem, str): for n in self._notes: if not hasattr(n, 'pitch'): continue if n.pitch.nameWithOctave == removeItem: self._notes.remove(n) self.clearCache() return raise ValueError('Chord.remove(x), x not in chord') if isinstance(removeItem, pitch.Pitch): for n in self._notes: if hasattr(n, 'pitch') and n.pitch == removeItem: self._notes.remove(n) self.clearCache() return raise ValueError('Chord.remove(x), x not in chord') if not isinstance(removeItem, note.NotRest): raise ValueError( f'Cannot remove {removeItem} from a chord; try a Pitch or Note object' ) try: self._notes.remove(removeItem) self.clearCache() except ValueError: raise ValueError('Chord.remove(x), x not in chord') @property def notes(self) -> tuple[note.NotRest, ...]: return tuple(self._notes) @property def tie(self) -> tie.Tie|None: ''' Get or set a single tie based on all the ties in this Chord. This overloads the behavior of the tie attribute found in all NotRest classes. If setting a tie, tie is applied to all pitches. >>> c1 = chord.Chord(['c4', 'g4']) >>> tie1 = tie.Tie('start') >>> c1.tie = tie1 >>> c1.tie >>> c1.getTie(c1.pitches[1]) ''' for d in self._notes: if d.tie is not None: return d.tie return None @tie.setter def tie(self, value: tie.Tie|None): for d in self._notes: d.tie = value # set the same instance for each pitch # d['tie'] = value @property def volume(self) -> 'music21.volume.Volume': # do NOT change to volume.Volume, see setter ''' Get or set the :class:`~music21.volume.Volume` object for this Chord. When setting the .volume property, all pitches are treated as having the same Volume object. >>> c = chord.Chord(['g#', 'd-']) >>> c.volume >>> c.volume = volume.Volume(velocity=64) >>> c.volume.velocityIsRelative = False >>> c.volume * Changed in v8: setting volume to a list of volumes is no longer supported. See :meth:`~music21.chord.ChordBase.setVolumes` instead OMIT_FROM_DOCS Make sure that empty chords have a volume: >>> chord.Chord().volume ''' if isinstance(self._volume, volume.Volume): # if we already have a Volume, use that return self._volume if not self.hasComponentVolumes(): # create a single new Volume object for the chord self._volume = volume.Volume(client=self) return self._volume # if we have components and _volume is None, create a volume from # components velocities = [] for inner_n in self._notes: if inner_n.volume.velocity is not None: velocities.append(inner_n.volume.velocity) # create new local object out_volume = volume.Volume(client=self) if velocities: # avoid division by zero error out_volume.velocity = int(round(sum(velocities) / len(velocities))) self._volume = out_volume return out_volume @volume.setter def volume(self, expr: None|'music21.volume.Volume'|int|float): # Do NOT change typing to volume.Volume w/o quotes because it will take the property as # its name and be really confused. if isinstance(expr, volume.Volume): expr.client = self # remove any component volumes for c in self._notes: c._volume = None note.NotRest._setVolume(self, expr, setClient=False) elif common.isNum(expr): vol = self._getVolume() if expr < 1: # assume a scalar vol.velocityScalar = float(expr) else: # assume velocity vol.velocity = int(expr) else: raise ChordException(f'unhandled setting expr: {expr}') def hasComponentVolumes(self) -> bool: ''' Utility method to determine if this object has component :class:`~music21.volume.Volume` objects assigned to each note-component. >>> c1 = chord.Chord(['c4', 'd-1', 'g6']) >>> c1.setVolumes([60, 20, 120]) >>> [n.volume.velocity for n in c1] [60, 20, 120] >>> c1.hasComponentVolumes() True >>> c2 = chord.Chord(['c4', 'd-1', 'g6']) >>> c2.volume.velocity = 23 >>> c2.hasComponentVolumes() False >>> c3 = chord.Chord(['c4', 'd-1', 'g6']) >>> c3.setVolumes([0.2, 0.5, 0.8]) >>> [n.volume.velocity for n in c3] [25, 64, 102] >>> c4 = chord.Chord(['c4', 'd-1', 'g6']) >>> c4.volume = 89 >>> c4.volume.velocity 89 >>> c4.hasComponentVolumes() False ''' count = 0 for c in self._notes: # access private attribute, as property will create otherwise if c.hasVolumeInformation(): count += 1 if count == len(self._notes): # environLocal.printDebug(['hasComponentVolumes:', True]) return True else: # environLocal.printDebug(['hasComponentVolumes:', False]) return False # -------------------------------------------------------------------------- # volume per pitch ?? # -------------------------------------------------------------------------- def setVolumes(self, volumes: Sequence['music21.volume.Volume'|int|float]): # do not change typing to volume.Volume -- will get the property of same name. # noinspection PyShadowingNames ''' Set as many individual volumes as appear in volumes. If there are not enough volumes, then cycles through the list of volumes here: >>> c = chord.Chord(['g#', 'd-']) >>> c.setVolumes([volume.Volume(velocity=96), volume.Volume(velocity=96)]) >>> c.hasComponentVolumes() True Note that this means that the chord itself does not have a volume at this moment! >>> c.hasVolumeInformation() False >>> c.volume.velocity 96 But after having called the volume, now it does: >>> c.hasVolumeInformation() True >>> c.volume.velocityIsRelative = False >>> c.volume * New in v8: replaces setting .volume to a list ''' # if setting components, remove single velocity self._volume = None for i, c in enumerate(self._notes): v_entry = volumes[i % len(volumes)] v: volume.Volume if isinstance(v_entry, volume.Volume): v = v_entry else: # create a new Volume if v_entry < 1: # assume a scalar v = volume.Volume(velocityScalar=float(v_entry)) else: # assume velocity v = volume.Volume(velocity=int(v_entry)) v.client = self c._setVolume(v, setClient=False) # ------------------------------------------------------------------------------ class Chord(ChordBase): ''' Class representing Chords. A Chord functions like a Note object but has multiple pitches. Create chords by passing a list of strings of pitch names: >>> dMaj = chord.Chord(['D', 'F#', 'A']) >>> dMaj Pitch names can also include octaves: >>> dMaj = chord.Chord(['D3', 'F#4', 'A5']) >>> dMaj A single string with note names separated by spaces also works: >>> myChord = chord.Chord('A4 C#5 E5') >>> myChord Or you can combine already created Notes or Pitches: >>> cNote = note.Note('C') >>> eNote = note.Note('E') >>> gNote = note.Note('G') And then create a chord with note objects: >>> cmaj = chord.Chord([cNote, eNote, gNote]) >>> cmaj # default octave of 4 is used for these notes, since octave was not specified Or with pitches: >>> cmaj2 = chord.Chord([pitch.Pitch('C'), pitch.Pitch('E'), pitch.Pitch('G')]) >>> cmaj2 Chord has the ability to determine the root of a chord, as well as the bass note of a chord. In addition, Chord is capable of determining what type of chord a particular chord is, whether it is a triad or a seventh, major or minor, etc., as well as what inversion the chord is in. A chord can also be created from pitch class numbers: >>> c = chord.Chord([0, 2, 3, 5]) >>> c.pitches (, , , ) Or from MIDI numbers: >>> c = chord.Chord([72, 76, 79]) >>> c.pitches (, , ) (If the number is < 12, it is assumed to be an octaveless pitch-class number, if above 12, then a MIDI number. To create chords below MIDI 12, create a Pitch object with that MIDI number instead and then pass that to the Chord creator). Duration or quarterLength also works: >>> d = duration.Duration(2.0) >>> myChord = chord.Chord('A4 C#5 E5', duration=d) >>> myChord >>> myChord.duration >>> myChord.duration is d True >>> myChord = chord.Chord('A4 C#5 E5', quarterLength=3.75) >>> myChord.duration.type 'half' >>> myChord.duration.dots 3 OMIT_FROM_DOCS Test that durations are being created efficiently: >>> dMaj.duration >>> cmaj.pitches[0] is cNote.pitch True >>> cNote.duration >>> cmaj.duration >>> cmaj.duration is cNote.duration True Create a chord from two chords (or a chord + notes): >>> eFlatSixFive = chord.Chord('G3 B-3 D-4 E-4') >>> fFlat = chord.Chord('F-2 A-2 C-3 F-3') >>> riteOfSpring = chord.Chord([fFlat, eFlatSixFive]) >>> riteOfSpring Incorrect entries raise a TypeError: >>> chord.Chord([base]) Traceback (most recent call last): TypeError: Could not process input argument **Equality** Two chords are equal if the Chord passes all `super()` equality tests and all their pitches are equal (possibly in a different order) >>> c1 = chord.Chord('C4 E4 G4') >>> c2 = chord.Chord('E4 C4 G4') >>> c1 == c2 True >>> c3 = chord.Chord('E4 C#4 G4') >>> c2 == c3 False >>> n1 = note.Note('C4') >>> c1 == n1 False >>> c2.duration.quarterLength = 2.0 >>> c1 == c2 False >>> c1 != c2 True ''' # CLASS VARIABLES # isChord = True # define order of presenting names in documentation; use strings _DOC_ORDER = ['pitches'] # documentation for all attributes (not properties or methods) _DOC_ATTR: dict[str, str] = { 'isChord': ''' Boolean read-only value describing if this GeneralNote object is a Chord. Is True''', } # update inherited _DOC_ATTR dictionary _DOC_ATTR.update(ChordBase._DOC_ATTR) # INITIALIZER # def __init__(self, notes: t.Union[None, Sequence[pitch.Pitch], Sequence[note.Note], Sequence[Chord], Sequence[str], str, Sequence[int]] = None, **keywords): if notes is not None and any(isinstance(n, note.GeneralNote) and not isinstance(n, (note.Note, Chord)) for n in notes): raise TypeError(f'Use a PercussionChord to contain Unpitched objects; got {notes}') super().__init__(notes=notes, **keywords) # if there were a covariant list, we would use that instead. self._notes: list[note.Note] # type: ignore if notes is not None and all(isinstance(n, int) for n in notes): self.simplifyEnharmonics(inPlace=True) # SPECIAL METHODS # def __eq__(self, other): if not super().__eq__(other): return False if set(self.pitches) != set(other.pitches): return False return True def __hash__(self): return super().__hash__() def __getitem__(self, key: int|str|note.Note|pitch.Pitch): ''' Get item makes accessing pitch components for the Chord easier >>> c = chord.Chord('C#4 D-4') >>> cSharp = c[0] >>> cSharp >>> c['0.step'] 'C' >>> c['3.accidental'] Traceback (most recent call last): KeyError: "Cannot access component with: '3.accidental'" >>> c[5] Traceback (most recent call last): KeyError: 'Cannot access component with: 5' >>> c['D-4'] >>> c['D-4.style.color'] is None True Getting by note does not do very much: >>> c[cSharp] But we can get from another note >>> cSharp2 = note.Note('C#4') >>> cSharp2.duration.quarterLength = 3.0 >>> c[cSharp2] is cSharp True >>> c[cSharp2] is cSharp2 False KeyError is raised if not in chord. >>> notInChord = note.Note('G') >>> c[notInChord] Traceback (most recent call last): KeyError: 'Cannot access component with: ' >>> c[None] Traceback (most recent call last): KeyError: 'Cannot access component with: None' ''' foundNote: note.Note attributes: tuple[str, ...] keyErrorStr = f'Cannot access component with: {key!r}' if isinstance(key, str): if '.' in key: key, attrStr = key.split('.', 1) if '.' in attrStr: attributes = tuple(attrStr.split('.')) else: attributes = (attrStr,) else: attributes = () try: key = int(key) except ValueError: pass else: attributes = () if isinstance(key, int): try: foundNote = self._notes[key] # must be a number except (KeyError, IndexError): raise KeyError(keyErrorStr) elif isinstance(key, str): key = key.upper() for n in self._notes: if n.pitch.nameWithOctave == key: foundNote = n break else: raise KeyError(keyErrorStr) elif isinstance(key, note.Note): for n in self._notes: if n is key: foundNote = n break else: for n in self._notes: if n.pitch == key.pitch: foundNote = n break else: raise KeyError(keyErrorStr) elif isinstance(key, pitch.Pitch): for n in self._notes: if n.pitch is key: foundNote = n break else: for n in self._notes: if n.pitch == key: foundNote = n break else: raise KeyError(keyErrorStr) else: raise KeyError(keyErrorStr) if not attributes: return foundNote currentValue: t.Any = foundNote for attr in attributes: if attr == 'volume': # special handling # noinspection PyArgumentList currentValue = currentValue._getVolume(forceClient=self) else: currentValue = getattr(currentValue, attr) return currentValue def __setitem__(self, key, value): ''' Change either a note in the chord components, or set an attribute on a component >>> c = chord.Chord('C4 E4 G4') >>> c[0] = note.Note('C#4') >>> c >>> c['0.octave'] = 3 >>> c >>> c['E4'] = 'F4' >>> c >>> c['G4.style.color'] = 'red' >>> c['G4.style.color'] 'red' >>> c[-1].style.color 'red' >>> c[0] = None Traceback (most recent call last): ValueError: Chord index must be set to a valid note object ''' if isinstance(key, str) and '.' in key: keySplit = key.split('.') keyFind = '.'.join(keySplit[0:-1]) attr = keySplit[-1] keyObj = self[keyFind] setattr(keyObj, attr, value) return keyObj = self[key] keyIndex = self._notes.index(keyObj) if isinstance(value, str): value = note.Note(value) elif isinstance(value, pitch.Pitch): value = note.Note(pitch=value) elif not isinstance(value, note.Note): raise ValueError('Chord index must be set to a valid note object') self._notes[keyIndex] = value def _reprInternal(self) -> str: if not self.pitches: return super()._reprInternal() allPitches = [] for thisPitch in self.pitches: allPitches.append(thisPitch.nameWithOctave) return ' '.join(allPitches) # STATIC METHOD # @staticmethod def formatVectorString(vectorList) -> str: ''' Return a string representation of a vector or set Static method. Works on the class: >>> chord.Chord.formatVectorString([0, 11]) '<0B>' or an existing chord: >>> c1 = chord.Chord(['D4', 'A4', 'F#5', 'D6']) >>> c1.formatVectorString(c1.normalOrder) '<269>' or on a list that has nothing to do with the chord >>> c1.formatVectorString([10, 11, 3, 5]) '' ''' msg = ['<'] for e in vectorList: # should be numbers eStr = pitch.convertPitchClassToStr(e) msg.append(eStr) msg.append('>') return ''.join(msg) # PRIVATE METHODS # def _findBass(self) -> pitch.Pitch|None: ''' Returns the lowest Pitch in the chord. The only time findBass should be called is by bass() when it is figuring out what the bass note of the chord is. Generally call bass() instead: >>> cmaj = chord.Chord(['C4', 'E3', 'G4']) >>> cmaj._findBass() ''' lowest = None for thisPitch in self.pitches: if lowest is None: lowest = thisPitch else: lowest = interval.getWrittenLowerNote(lowest, thisPitch) return lowest def _removePitchByRedundantAttribute( self: _ChordType, attribute: str, *, inPlace=False ) -> _ChordType|list[pitch.Pitch]: ''' Common method for stripping pitches based on redundancy of one pitch attribute. The `attribute` is provided by a string. ''' if not inPlace: # make a copy returnObj = copy.deepcopy(self) else: returnObj = self uniquePitches = [] deleteComponents = [] for comp in returnObj._notes: if getattr(comp.pitch, attribute) not in uniquePitches: uniquePitches.append(getattr(comp.pitch, attribute)) else: deleteComponents.append(comp) # environLocal.printDebug(['unique, delete', self, unique, delete]) altered = returnObj._notes alteredId = [id(n) for n in altered] for n in deleteComponents: nIndex = alteredId.index(id(n)) altered.pop(nIndex) alteredId.pop(nIndex) returnObj._notes = altered if deleteComponents: returnObj.clearCache() if not inPlace: return returnObj else: return [n.pitch for n in deleteComponents] # PUBLIC METHODS # def add( self, notes, *, runSort=True ) -> None: ''' Add a Note, Pitch, the `.notes` of another chord, or string representing a pitch, or a list of any-of-the-above types to a Chord. If `runSort` is True (default=True) then after appending, the chord will be sorted. >>> c = chord.Chord('C4 E4 G4') >>> c.add('B3') >>> c >>> c.duration >>> c.add('A2', runSort=False) >>> c >>> c.add(['B5', 'C6']) >>> c >>> c.add(pitch.Pitch('D6')) >>> c >>> n = note.Note('E6') >>> n.duration.type = 'half' >>> c.add(n) >>> c >>> c.duration >>> c[-1] >>> c[-1].duration Overrides `ChordBase.add()` to permit sorting with `runSort`. ''' if not common.isIterable(notes): notes = [notes] if any(isinstance(n, note.Unpitched) for n in notes): raise TypeError(f'Use a PercussionChord to contain Unpitched objects; got {notes}') super().add(notes) if runSort: self.sortAscending(inPlace=True) @overload def annotateIntervals( self: _ChordType, *, inPlace: bool = False, stripSpecifiers: bool = True, sortPitches: bool = True, returnList: t.Literal[True] ) -> list[str]: ... @overload def annotateIntervals( self: _ChordType, *, inPlace: t.Literal[True], stripSpecifiers: bool = True, sortPitches: bool = True, returnList: t.Literal[False] = False ) -> None: ... @overload def annotateIntervals( self: _ChordType, *, inPlace: t.Literal[False] = False, stripSpecifiers: bool = True, sortPitches: bool = True, returnList: t.Literal[False] = False ) -> _ChordType: ... def annotateIntervals( self: _ChordType, *, inPlace: bool = False, stripSpecifiers: bool = True, sortPitches: bool = True, returnList: bool = False ) -> _ChordType|None|list[str]: # noinspection PyShadowingNames ''' Add lyrics to the chord that show the distance of each note from the bass. If returnList is True, a list of the intervals is returned instead. By default, we show only the generic interval: >>> c1 = chord.Chord(['C2', 'E2', 'G2', 'C3']) >>> c2 = c1.annotateIntervals(inPlace=False) >>> c2.lyrics [, , ] >>> [ly.text for ly in c2.lyrics] ['8', '5', '3'] The `stripSpecifiers` parameter can be used to show only the intervals size (3, 5, etc.) or the complete interval specification (m3, P5, etc.) >>> c3 = c1.annotateIntervals(inPlace=False, stripSpecifiers=False) >>> c3.lyrics [, , ] >>> [ly.text for ly in c3.lyrics] ['P8', 'P5', 'M3'] This chord was giving us problems: >>> c4 = chord.Chord(['G4', 'E4', 'B3', 'E3']) >>> c4.annotateIntervals(inPlace=True, stripSpecifiers=False) >>> [ly.text for ly in c4.lyrics] ['m3', 'P8', 'P5'] >>> c4.annotateIntervals(inPlace=True, stripSpecifiers=False, returnList=True) ['m3', 'P8', 'P5'] If sortPitches is false it still gives problems: >>> c4 = chord.Chord(['G4', 'E4', 'B3', 'E3']) >>> c4.annotateIntervals(inPlace=True, stripSpecifiers=False, sortPitches=False) >>> [ly.text for ly in c4.lyrics] ['m3', 'm6', 'm3'] >>> c = chord.Chord(['c4', 'd-4', 'g4']) >>> c.annotateIntervals(inPlace=True) >>> [ly.text for ly in c.lyrics] ['5', '2'] >>> c = chord.Chord(['c4', 'd-4', 'g4']) >>> c.annotateIntervals(inPlace=True, stripSpecifiers=False) >>> [ly.text for ly in c.lyrics] ['P5', 'm2'] >>> c = chord.Chord(['c4', 'd---4', 'g4']) >>> c.annotateIntervals(inPlace=True, stripSpecifiers=False) >>> [ly.text for ly in c.lyrics] ['P5', 'dd2'] >>> c = chord.Chord(['c4', 'g5', 'e6']) >>> c.annotateIntervals(inPlace=True) >>> [ly.text for ly in c.lyrics] ['5', '3'] ''' # make a copy of self for reducing pitches, but attach to self c = copy.deepcopy(self) # this could be an option c.removeRedundantPitches(inPlace=True) if sortPitches: c = c.sortAscending() # environLocal.printDebug(['annotateIntervals()', c.pitches]) lyricsList = [] for j in range(len(c.pitches) - 1, 0, -1): # only go to one; zero never used p = c.pitches[j] i = interval.Interval(c.pitches[0], p) if stripSpecifiers is False: notation = i.semiSimpleName else: notation = str(i.diatonic.generic.semiSimpleUndirected) lyricsList.append(notation) if stripSpecifiers and sortPitches: lyricsList.sort(reverse=True) if returnList: return lyricsList for notation in lyricsList: if inPlace: self.addLyric(notation) else: c.addLyric(notation) if not inPlace: return c def areZRelations(self: _ChordType, other: _ChordType) -> bool: ''' Check if another Chord is a z-relation to this Chord. >>> c1 = chord.Chord(['C', 'c#', 'e', 'f#']) >>> c2 = chord.Chord(['C', 'c#', 'e-', 'g']) >>> c3 = chord.Chord(['C', 'c#', 'f#', 'g']) >>> c1.areZRelations(c2) True >>> c1.areZRelations(c3) False If there is no z-relation for the first chord, obviously return False: >>> c4 = chord.Chord('C E G') >>> c4.areZRelations(c3) False ''' zRelationAddress = tables.addressToZAddress(self.chordTablesAddress) if zRelationAddress is None: return False if other.chordTablesAddress[0:3] == zRelationAddress[0:3]: return True return False @overload def bass( self, newbass: None = None, *, find: bool|None = None, allow_add: bool = False, ) -> pitch.Pitch: ... @overload def bass( self, newbass: str|pitch.Pitch|note.Note, *, find: bool|None = None, allow_add: bool = False, ) -> None: ... def bass( self, newbass: None|str|pitch.Pitch|note.Note = None, *, find: bool|None = None, allow_add: bool = False, ) -> pitch.Pitch|None: ''' Generally used to find and return the bass Pitch: >>> cmaj1stInv = chord.Chord(['C4', 'E3', 'G5']) >>> cmaj1stInv.bass() Subclasses of Chord often have basses that are harder to determine. >>> cmaj = harmony.ChordSymbol('CM') >>> cmaj.bass() >>> cmin_inv = harmony.ChordSymbol('Cm/E-') >>> cmin_inv.bass() Can also be used in rare occasions to set the bass note to a new Pitch, so long as that note is found in the chord: >>> strange_chord = chord.Chord('E##4 F-4 C5') >>> strange_chord.bass() >>> strange_chord.bass('F-4') >>> strange_chord.bass() If the note assigned to the bass is not found, it will default to raising a ChordException: >>> strange_chord.bass('G--4') Traceback (most recent call last): music21.chord.ChordException: Pitch G--4 not found in chord For the purposes of initializing from a ChordSymbol and in other cases, a new bass can be added to the chord by setting `allow_add = True`: >>> strange_chord.bass('G--4', allow_add=True) >>> strange_chord.bass() By default, if nothing has been overridden, this method uses a quick algorithm to find the bass among the chord's pitches, if no bass has been previously specified. If this is not intended, set find to False when calling this method, and 'None' will be returned if no bass is specified >>> em = chord.Chord(['E3', 'G3', 'B4']) >>> print(em.bass(find=False)) None * Changed in v8: raise an exception if setting a new bass to a pitch not in the chord, unless new keyword `allow_add` is `True`. OMIT_FROM_DOCS Test to make sure that cached basses still work by calling twice: >>> a = chord.Chord(['C4']) >>> a.bass() >>> a.bass() # After changing behavior uncomment these lines. # Setting a new bass note might be helpful to move it to a different # octave. Otherwise, it is likely just to lead to confusion and # hard to diagnose errors. # # >>> cmin_inv.bass('E-2') # >>> cmin_inv.bass() # # # To find the bass again from the pitches in the chord, set find=True # # >>> cmin_inv.bass(find=True) # # # Subsequent calls after an overridden bass has been cleared by find=True # will continue to return the algorithmically determined bass. # # >>> cmin_inv.bass() # ''' if newbass: newbassPitch: pitch.Pitch if isinstance(newbass, str): newbass = common.cleanedFlatNotation(newbass) newbassPitch = pitch.Pitch(newbass) elif isinstance(newbass, pitch.Pitch): newbassPitch = newbass elif isinstance(newbass, note.Note): newbassPitch = newbass.pitch else: raise ChordException(f'newbass should be a Pitch, not {type(newbass)}') # try to set newbass to be a pitch in the chord if possible foundBassInChord: bool = False for p in self.pitches: # first by identity if newbassPitch is p: foundBassInChord = True break if not foundBassInChord: for p in self.pitches: # then by name with octave if p.nameWithOctave == newbassPitch.nameWithOctave: newbassPitch = p foundBassInChord = True break if not foundBassInChord: # finally by name for p in self.pitches: if p.name == newbassPitch.name: foundBassInChord = True newbassPitch = p break if not foundBassInChord: # it's not there, needs to be added if not allow_add: raise ChordException(f'Pitch {newbass} not found in chord') self.pitches = (newbassPitch, *(p for p in self.pitches)) self._overrides['bass'] = newbassPitch self._cache['bass'] = newbassPitch if 'inversion' in self._cache: del self._cache['inversion'] # reset inversion if bass changes return None if 'bass' in self._overrides and find is not True: return self._overrides['bass'] if find is False: return None if 'bass' in self._overrides: del self._overrides['bass'] if find is not True and 'bass' in self._cache: return self._cache['bass'] else: self._cache['bass'] = self._findBass() return self._cache['bass'] def canBeDominantV(self) -> bool: ''' Returns True if the chord is a Major Triad or a Dominant Seventh: >>> gSeven = chord.Chord(['g', 'b', 'd', 'f']) >>> gSeven.canBeDominantV() True >>> gDim = chord.Chord(['g', 'b-', 'd-']) >>> gDim.canBeDominantV() False ''' if self.isMajorTriad() or self.isDominantSeventh(): return True else: return False def canBeTonic(self) -> bool: ''' Returns True if the chord is a major or minor triad: >>> a = chord.Chord(['g', 'b', 'd', 'f']) >>> a.canBeTonic() False >>> a = chord.Chord(['g', 'b', 'd']) >>> a.canBeTonic() True ''' if self.isMajorTriad() or self.isMinorTriad(): return True else: return False @overload def closedPosition( self: _ChordType, *, forceOctave: int|None = None, inPlace: t.Literal[True], leaveRedundantPitches: bool = False ) -> None: ... @overload def closedPosition( self: _ChordType, *, forceOctave: int|None = None, inPlace: t.Literal[False] = False, leaveRedundantPitches: bool = False ) -> _ChordType: ... def closedPosition( self: _ChordType, *, forceOctave: int|None = None, inPlace: bool = False, leaveRedundantPitches: bool = False ) -> _ChordType|None: ''' Returns a new Chord object with the same pitch classes, but now in closed position. If `forcedOctave` is provided, the bass of the chord will be shifted to that provided octave. If inPlace is True then the original chord is returned with new pitches. >>> chord1 = chord.Chord(['C#4', 'G5', 'E6']) >>> chord2 = chord1.closedPosition() >>> chord2 Force octave changes the octave of the bass note (and all notes above it) >>> c2 = chord.Chord(['C#4', 'G5', 'E6']) >>> c2.closedPosition(forceOctave=2) >>> c3 = chord.Chord(['C#4', 'G5', 'E6']) >>> c3.closedPosition(forceOctave=6) Redundant pitches are removed by default, but can be retained: >>> c4 = chord.Chord(['C#4', 'C5', 'F7', 'F8']) >>> c5 = c4.closedPosition(forceOctave=4, inPlace=False) >>> c5 >>> c6 = c4.closedPosition(forceOctave=4, inPlace=False, leaveRedundantPitches=True) >>> c6 Implicit octaves work fine: >>> c7 = chord.Chord(['A4', 'B4', 'A']) >>> c7.closedPosition(forceOctave=4, inPlace=True) >>> c7 OMIT_FROM_DOCS Very specialized fears: Duplicate octaves were not working >>> c7b = chord.Chord(['A4', 'B4', 'A5']) >>> c7b.closedPosition(inPlace=True) >>> c7b but the bass must remain A4: >>> c7c = chord.Chord(['A4', 'B4', 'A5', 'G##6']) >>> c7c.closedPosition(inPlace=True) >>> c7c >>> str(c7c.bass()) 'A4' Complex chord for semiclosed-position testing: >>> c8 = chord.Chord(['C3', 'E5', 'C#6', 'E-7', 'G8', 'C9', 'E#9']) >>> c8.closedPosition(inPlace=True) >>> c8 Implicit octave + forceOctave >>> c9 = chord.Chord('C G E') >>> c9.closedPosition(forceOctave=6) ''' # environLocal.printDebug(['calling closedPosition()', inPlace]) if inPlace: returnObj = self else: returnObj = copy.deepcopy(self) returnObj.derivation = derivation.Derivation(returnObj) returnObj.derivation.origin = self returnObj.derivation.method = 'closedPosition' # tempChordNotes = returnObj.pitches pBass = returnObj.bass() # returns a reference, not a copy if forceOctave is not None: pBassOctave = pBass.octave if pBassOctave is None: pBassOctave = pBass.implicitOctave if pBassOctave > forceOctave: dif = -1 elif pBassOctave < forceOctave: dif = 1 else: # equal dif = None if dif is not None: while pBass.octave != forceOctave: # shift octave of all pitches for p in returnObj.pitches: if p.octave is None: p.octave = p.implicitOctave p.octave += dif # can change these pitches in place for p in returnObj.pitches: # bring each pitch down octaves until pitch space is # within an octave if p.octave is None: p.octave = p.implicitOctave while p.ps >= pBass.ps + 12: p.octave -= 1 # check for a bass of C4 and the note B#7 added to it, should be B#4 not B#3... if p.diatonicNoteNum < pBass.diatonicNoteNum: p.octave += 1 if leaveRedundantPitches is not True: returnObj.removeRedundantPitches(inPlace=True) # here we can always be in place # if not inPlace, creates a second new chord object! returnObj.sortAscending(inPlace=True) if not inPlace: return returnObj def containsSeventh(self) -> bool: ''' Returns True if the chord contains at least one of each of Third, Fifth, and Seventh. raises an exception if the Root can't be determined A ninth chord contains a seventh: >>> c9 = chord.Chord(['C4', 'E4', 'G4', 'B4', 'D5']) >>> c9.containsSeventh() True As does a cluster: >>> cluster = chord.Chord('C D E F G A B') >>> cluster.containsSeventh() True But a major triad does not: >>> dMaj = chord.Chord([pitch.Pitch('D4'), pitch.Pitch('F#4'), pitch.Pitch('A5')]) >>> dMaj.containsSeventh() False Note that a seventh chord itself contains a seventh. >>> cChord = chord.Chord(['C', 'E', 'G', 'B']) >>> cChord.containsSeventh() True Empty chord returns False >>> chord.Chord().containsSeventh() False ''' if not self.containsTriad(): return False # no need to cache, since third, fifth, and seventh are cached if self.seventh is None: return False return True def containsTriad(self) -> bool: ''' Returns True or False if there is no triad above the root. "Contains vs. Is": A dominant-seventh chord contains a triad. >>> cChord = chord.Chord(['C', 'E', 'G']) >>> other = chord.Chord(['C', 'D', 'E', 'F', 'G']) >>> cChord.containsTriad() True >>> other.containsTriad() True >>> scale = chord.Chord(['C', 'D-', 'E', 'F#', 'G', 'A#', 'B']) >>> scale.containsTriad() True >>> c = chord.Chord('C4 D4') >>> c.containsTriad() False >>> chord.Chord().containsTriad() False ''' # no need to cache, since third and fifth are cached if self.third is None: return False if self.fifth is None: return False return True def _findRoot(self) -> pitch.Pitch: ''' Looks for the root usually by finding the note with the most 3rds above it. Generally use root() instead, since if a chord doesn't know its root, root() will run ._findRoot() automatically. ''' def rootnessFunction(rootThirdList): ''' Returns a value for how likely this pitch is to be a root given the number of thirds and fifths above it. Takes a list of True's and False's where each value represents whether a note has a 3rd, 5th, 7th, 9th, 11th, and 13th above it and calculates a value based on that. The highest score on rootnessFunction is the root. This formula might be tweaked if wrong notes are found. Rootness function might be divided by the inversion number in case that's a problem. ''' score = 0 for root_index, val in enumerate(rootThirdList): if val is True: score += 1 / (root_index + 6) return score # FIND ROOT FAST -- for cases where one note has perfectly stacked # thirds, like E C G; but not C E B- # if one pitch has perfectlyStackedThirds, return it always. # we use the music21 unique function since it preserves the order nonDuplicatingPitches = common.misc.unique((n.pitch for n in self._notes), key=lambda pp: pp.step) lenPitches = len(nonDuplicatingPitches) if not lenPitches: raise ChordException(f'no pitches in chord {self!r}') if lenPitches == 1: return self.pitches[0] elif lenPitches == 7: # 13th chord return self.bass() stepNumsToPitches: dict[int, pitch.Pitch] = {pitch.STEP_TO_DNN_OFFSET[p.step]: p for p in nonDuplicatingPitches} # TODO: duplicate the steps array [1,0,1,0,1,0,0] so it's [1,0,1,0,1,0,0,1,0,1,0,1,0,0] # and then for each cardinality, use a template like [1, 0, 1, 0, 1] to slide along # and see if it fits -- this will allow this routine to work for any number of # steps from 3-6. stepNums = sorted(stepNumsToPitches) for startIndex in range(lenPitches): all_are_thirds = True this_step_num = stepNums[startIndex] last_step_num = this_step_num for endIndex in range(startIndex + 1, startIndex + lenPitches): endIndexMod = endIndex % lenPitches endStepNum = stepNums[endIndexMod] if endStepNum - last_step_num not in (2, -5): all_are_thirds = False break last_step_num = endStepNum if all_are_thirds: return stepNumsToPitches[this_step_num] # FIND ROOT SLOW # no notes (or more than one) have perfectlyStackedThirds above them. Return # the highest scoring note # this is the slowest rootnessFunctionScores = [] orderedChordSteps = (3, 5, 7, 2, 4, 6) for p in nonDuplicatingPitches: currentListOfThirds = [] this_step_num = pitch.STEP_TO_DNN_OFFSET[p.step] for chordStepTest in orderedChordSteps: if (this_step_num + chordStepTest - 1) % 7 in stepNumsToPitches: currentListOfThirds.append(True) else: currentListOfThirds.append(False) rootnessScore = rootnessFunction(currentListOfThirds) rootnessFunctionScores.append(rootnessScore) mostRootyIndex = rootnessFunctionScores.index(max(rootnessFunctionScores)) return nonDuplicatingPitches[mostRootyIndex] def geometricNormalForm(self) -> list[int]: ''' Geometric Normal Form, as first defined by Dmitri Tymoczko, orders pitch classes such that the spacing is prioritized with the smallest spacing between the first and second pitch class first, then the smallest spacing between second and third pitch class, and so on. This form has unique properties that make it useful. It also transposes to PC0 `geometricNormalForm` returns a list of pitch class integers in geometric normal form. Example 1: A major triad has geometricNormalForm of 038 not 047. >>> c1 = chord.Chord('E4 C5 G6 C7') >>> pcList = c1.geometricNormalForm() >>> pcList [0, 3, 8] >>> c2 = chord.Chord(pcList) >>> c2.orderedPitchClassesString '<038>' Compare this to the usual normalOrder transposed to PC0: >>> normalOrder = c1.normalOrder >>> normalOrderFirst = normalOrder[0] >>> [(pc - normalOrderFirst) % 12 for pc in normalOrder] [0, 4, 7] ''' # no need to cache, since only DT uses it # Order pitches pitchClassList = [] for i in range(len(self.pitches)): pitchClassList.append(self.pitches[i].pitchClass) sortedPitchClassList = sorted(pitchClassList) # Remove duplicates uniquePitchClassList = [sortedPitchClassList[0]] for i in range(1, len(sortedPitchClassList)): if sortedPitchClassList[i] != sortedPitchClassList[i - 1]: uniquePitchClassList.append(sortedPitchClassList[i]) intervalList = [] for i in range(1, len(uniquePitchClassList)): lPC = (uniquePitchClassList[i] - uniquePitchClassList[i - 1]) % 12 intervalList.append(lPC) intervalList.append((uniquePitchClassList[0] - uniquePitchClassList[-1]) % 12) # make list of rotations rotationList = [] for i in range(0, len(intervalList)): b = intervalList.pop(0) intervalList.append(b) intervalTuple = tuple(intervalList) rotationList.append(intervalTuple) # Sort list of rotations. # First entry will be the geometric normal form arranged intervals newRotationList = sorted(rotationList) # Take that first entry and assign it as the PCIs that we will want for our chord geomNormChord = newRotationList[0] # Create final form of Geometric Normal Chord by starting at pc 0 and # assigning the notes based on the intervals we just discovered. geomNormChordPitches = [] intervalSum = 0 for i in range(0, len(geomNormChord)): geomNormChordPitches.append(intervalSum) intervalSum += geomNormChord[i] return geomNormChordPitches def getChordStep( self, chordStep: int, *, testRoot: note.Note|pitch.Pitch|None = None ) -> pitch.Pitch|None: ''' Returns the (first) pitch at the provided scaleDegree (Thus, it's exactly like semitonesFromChordStep, except it instead of the number of semitones.) Returns None if none can be found. >>> cmaj = chord.Chord(['C', 'E', 'G']) >>> cmaj.getChordStep(3) # will return the third of the chord >>> g = cmaj.getChordStep(5) # will return the fifth of the chord >>> g.name 'G' >>> cmaj.getChordStep(6) is None True Ninths can be specified with either 9 or 2. Similarly for elevenths and thirteenths. >>> c9 = chord.Chord('C4 E4 G4 B4 D5') >>> c9.getChordStep(9) >>> c9.getChordStep(2) OMIT_FROM_DOCS If `root` has been explicitly overridden as `None`, calling this raises `ChordException`: >>> cmaj._overrides['root'] = None >>> cmaj.getChordStep(6) Traceback (most recent call last): music21.chord.ChordException: Cannot run getChordStep without a root (This is in OMIT_FROM_etc.) ''' if chordStep >= 8: chordStep -= 7 testRootPitch: pitch.Pitch if testRoot is None: testRootPitch = self.root() # raises ChordException if no pitches if testRootPitch is None: # if root was overridden to be None raise ChordException('Cannot run getChordStep without a root') elif isinstance(testRoot, note.Note): testRootPitch = testRoot.pitch elif isinstance(testRoot, pitch.Pitch): testRootPitch = testRoot else: raise ChordException(f'testRoot should be a Pitch, not {type(testRoot)}') rootDNN = testRootPitch.diatonicNoteNum for thisPitch in self.pitches: diatonicDistance = ((thisPitch.diatonicNoteNum - rootDNN) % 7) + 1 if diatonicDistance == chordStep: return thisPitch return None def getColor( self, pitchTarget ): # noinspection PyShadowingNames ''' For a pitch in this Chord, return the color stored in self.editorial, or, if set for each component, return the color assigned to this component. First checks for "is" then "equals" >>> p = pitch.Pitch('C4') >>> n = note.Note(p) >>> n.style.color = 'red' >>> c = chord.Chord([n, 'E4']) >>> c.getColor(p) 'red' >>> c.getColor('C4') 'red' >>> c.getColor('E4') is None True The color of any pitch (even a non-existing one) is the color of the chord if the color of that pitch is not defined. >>> c.style.color = 'pink' >>> c.getColor('E4') 'pink' >>> c.getColor('D#7') 'pink' ''' if isinstance(pitchTarget, str): pitchTarget = pitch.Pitch(pitchTarget) for n in self._notes: if n.pitch is pitchTarget: if n.hasStyleInformation and n.style.color is not None: return n.style.color for n in self._notes: if n.pitch == pitchTarget: if n.hasStyleInformation and n.style.color is not None: return n.style.color if self.hasStyleInformation: return self.style.color # may be None else: return None def getNotehead(self, p): ''' Given a pitch in this Chord, return an associated notehead attribute, or return 'normal' if not defined for that Pitch. If the pitch is not found, None will be returned. >>> n1 = note.Note('D4') >>> n2 = note.Note('G4') >>> n2.notehead = 'diamond' >>> c1 = chord.Chord([n1, n2]) >>> c1.getNotehead(c1.pitches[1]) 'diamond' >>> c1.getNotehead(c1.pitches[0]) 'normal' >>> c1.getNotehead(pitch.Pitch('A#6')) is None True Will work if the two notes are equal in pitch >>> c1.getNotehead(note.Note('G4')) 'diamond' ''' if hasattr(p, 'pitch'): p = p.pitch for d in self._notes: if d.pitch is p: return d.notehead for d in self._notes: if d.pitch == p: return d.notehead return None def getNoteheadFill(self, p): ''' Given a pitch in this Chord, return an associated noteheadFill attribute, or return None if not defined for that Pitch. If the pitch is not found, None will also be returned. >>> n1 = note.Note('D4') >>> n2 = note.Note('G4') >>> n2.noteheadFill = True >>> c1 = chord.Chord([n1, n2]) >>> c1.getNoteheadFill(c1.pitches[1]) True >>> print(c1.getNoteheadFill(c1.pitches[0])) None >>> c1.getNoteheadFill(pitch.Pitch('A#6')) is None True Will work if the two notes are equal in pitch >>> c1.getNoteheadFill(note.Note('G4')) True Returns None if the pitch is not in the Chord: ''' if hasattr(p, 'pitch'): p = p.pitch for d in self._notes: if d.pitch is p: return d.noteheadFill for d in self._notes: if d.pitch == p: return d.noteheadFill return None def getStemDirection(self, p): ''' Given a pitch in this Chord, return an associated stem attribute, or return 'unspecified' if not defined for that Pitch or None. If the pitch is not found, None will be returned. >>> n1 = note.Note('D4') >>> n2 = note.Note('G4') >>> n2.stemDirection = 'double' >>> c1 = chord.Chord([n1, n2]) >>> c1.getStemDirection(c1.pitches[1]) 'double' >>> c1.getStemDirection(c1.pitches[0]) 'unspecified' Will work if the two pitches are equal in pitch >>> c1.getStemDirection(note.Note('G4')) 'double' Returns None if a Note or Pitch is not in the Chord >>> c1.getStemDirection(pitch.Pitch('A#4')) is None True ''' if hasattr(p, 'pitch'): p = p.pitch for d in self._notes: if d.pitch is p: # compare by obj id first return d.stemDirection for d in self._notes: if d.pitch == p: return d.stemDirection return None def getTie(self, p): ''' Given a pitch in this Chord, return an associated Tie object, or return None if not defined for that Pitch. >>> c1 = chord.Chord(['d', 'e-', 'b-']) >>> t1 = tie.Tie('start') >>> c1.setTie(t1, c1.pitches[2]) # just to b- >>> c1.getTie(c1.pitches[2]) == t1 True >>> c1.getTie(c1.pitches[0]) is None True All notes not in chord return None >>> c1.getTie(pitch.Pitch('F#2')) is None True >>> c1.getTie('B-') ''' try: return self[p].tie except KeyError: return None def getVolume(self, p): ''' For a given Pitch in this Chord, return the :class:`~music21.volume.Volume` object. Raises an exception if the pitch isn't in the chord (TODO: consider changing to be like notehead, etc.) >>> c = chord.Chord('C4 F4') >>> c[0].volume = 2 >>> c.getVolume('C4') >>> c.getVolume('F4') # default >>> c.getVolume('G4') Traceback (most recent call last): music21.chord.ChordException: the given pitch is not in the Chord: G4 ''' try: n = self[p] # noinspection PyArgumentList return n._getVolume(forceClient=self) except KeyError: raise ChordException(f'the given pitch is not in the Chord: {p}') def getZRelation(self) -> Chord|None: ''' Return a Z relation if it exists, otherwise return None. >>> chord.fromIntervalVector((1, 1, 1, 1, 1, 1)) >>> chord.fromIntervalVector((1, 1, 1, 1, 1, 1)).getZRelation() Z relation will always be zero indexed: >>> c = chord.Chord('D D# F# G#') >>> c.getZRelation() >>> chord.Chord('C E G').getZRelation() is None True ''' if self.hasZRelation: chordTablesAddress = self.chordTablesAddress v = tables.addressToIntervalVector(chordTablesAddress) addresses = tables.intervalVectorToAddress(v) # environLocal.printDebug(['addresses', addresses, # 'chordTablesAddress', chordTablesAddress]) # addresses returned here are 2 elements lists other = None for thisAddress in addresses: if thisAddress.forteClass != chordTablesAddress.forteClass: other = thisAddress # other should always be defined to not None prime = tables.addressToTransposedNormalForm(other) return Chord(prime) return None # c2.getZRelations() # needs a plural form returning a list in non-ET12 space # def hasAnyEnharmonicSpelledPitches(self) -> bool: ''' Returns True if for any given pitchClass there is at most one spelling of the note (in any octave). >>> cChord = chord.Chord('C4 E4 G4 C5') >>> cChord.hasAnyEnharmonicSpelledPitches() False Notice that having a C in two different octaves is no problem. However, this is False: >>> cChord = chord.Chord('C4 E4 G4 B#4') >>> cChord.hasAnyEnharmonicSpelledPitches() True ''' if len(self._unorderedPitchClasses()) != len(set(p.name for p in self.pitches)): return True else: return False def hasAnyRepeatedDiatonicNote(self) -> bool: ''' Returns True if for any diatonic note (e.g., C or C# = C) there are two or more different notes (such as E and E-) in the chord. If there are no repeated scale degrees, return False. >>> cChord = chord.Chord(['C', 'E', 'E-', 'G']) >>> cChord.hasAnyRepeatedDiatonicNote() True This routine is helpful for anything that works with Generic intervals and chord steps such as `.third` which makes sure that checking for root, second, third, ..., seventh will actually find all the different notes. This following example returns False because chromatically identical notes of different scale degrees do not count as a repeated diatonic note. (See :meth:`~music21.chord.Chord.hasAnyEnharmonicSpelledPitches` for that method) >>> other = chord.Chord(['C', 'E', 'F-', 'G']) >>> other.hasAnyRepeatedDiatonicNote() False ''' if len(set(p.step for p in self.pitches)) != len(set(p.name for p in self.pitches)): return True else: return False def hasRepeatedChordStep(self, chordStep, *, testRoot=None): ''' Returns True if chordStep above testRoot (or self.root()) has two or more different notes (such as E and E-) in it. Otherwise returns False. >>> cChord = chord.Chord(['G2', 'E4', 'E-5', 'C6']) >>> cChord.hasRepeatedChordStep(3) True >>> cChord.hasRepeatedChordStep(5) False ''' if testRoot is None: testRoot = self.root() if testRoot is None: raise ChordException('Cannot run hasRepeatedChordStep without a root') first = self.intervalFromChordStep(chordStep) for thisPitch in self.pitches: thisInterval = interval.Interval(testRoot, thisPitch) if thisInterval.diatonic.generic.mod7 == chordStep: if thisInterval.chromatic.mod12 - first.chromatic.mod12 != 0: return True return False def intervalFromChordStep(self, chordStep, *, testRoot=None): ''' Exactly like semitonesFromChordStep, except it returns the interval itself instead of the number of semitones: >>> cmaj = chord.Chord(['C', 'E', 'G']) >>> cmaj.intervalFromChordStep(3) # will return the interval between C and E >>> cmaj.intervalFromChordStep(5) # will return the interval between C and G >>> print(cmaj.intervalFromChordStep(6)) None ''' if testRoot is None: try: testRoot = self.root() except ChordException: raise ChordException('Cannot run intervalFromChordStep without a root') if testRoot is None: raise ChordException('Cannot run intervalFromChordStep without a root') for thisPitch in self.pitches: thisInterval = interval.Interval(testRoot, thisPitch) if thisInterval.diatonic.generic.mod7 == chordStep: return thisInterval return None @overload def inversion( self, newInversion: int, *, find: bool = True, testRoot: pitch.Pitch|None = None, transposeOnSet: bool = True ) -> None: ... @overload def inversion( self, newInversion: None = None, *, find: bool = True, testRoot: pitch.Pitch|None = None, transposeOnSet: bool = True ) -> int: ... def inversion( self, newInversion: int|None = None, *, find: bool = True, testRoot: pitch.Pitch|None = None, transposeOnSet: bool = True, ) -> int|None: ''' Find the chord's inversion or (if called with a number) set the chord to the new inversion. When called without a number argument, returns an integer (or None) representing which inversion (if any) the chord is in. The Chord does not have to be complete, in which case this function determines the inversion by looking at the relationship of the bass note to the root. Returns a maximum value of 5 for the fifth inversion of a thirteenth chord. Returns 0 if the bass to root interval is a unison or if interval is not a common inversion (1st-5th). The octave of the bass and root are irrelevant to this calculation of inversion. Returns None if the Chord has no pitches. >>> g7 = chord.Chord(['g4', 'b4', 'd5', 'f5']) >>> g7.inversion() 0 >>> g7.inversion(1) >>> g7 With implicit octaves, D becomes the bass (since octaves start on C): >>> g7_implicit = chord.Chord(['g', 'b', 'd', 'f']) >>> g7_implicit.inversion() 2 Note that in inverting a chord with implicit octaves, some pitches will gain octave designations, but not necessarily all of them (this behavior might change in the future): >>> g7_implicit.inversion(1) >>> g7_implicit Examples of each inversion: >>> cTriad1stInversion = chord.Chord(['E1', 'G1', 'C2']) >>> cTriad1stInversion.inversion() 1 >>> cTriad2ndInversion = chord.Chord(['G1', 'E2', 'C2']) >>> cTriad2ndInversion.inversion() 2 >>> dSeventh3rdInversion = chord.Chord(['C4', 'B4']) >>> dSeventh3rdInversion.bass(pitch.Pitch('B4')) >>> dSeventh3rdInversion.inversion() 3 >>> gNinth4thInversion = chord.Chord(['G4', 'B4', 'D5', 'F5', 'A4']) >>> gNinth4thInversion.bass(pitch.Pitch('A4')) >>> gNinth4thInversion.inversion() 4 >>> bbEleventh5thInversion = chord.Chord(['B-', 'D', 'F', 'A', 'C', 'E-']) >>> bbEleventh5thInversion.bass(pitch.Pitch('E-4')) >>> bbEleventh5thInversion.inversion() 5 Repeated notes do not affect the inversion: >>> gMajRepeats = chord.Chord(['G4', 'B5', 'G6', 'B6', 'D7']) >>> gMajRepeats.inversion(2) >>> gMajRepeats >>> gMajRepeats.inversion(3) Traceback (most recent call last): music21.chord.ChordException: Could not invert chord: inversion may not exist If testRoot is True then that temporary root is used instead of self.root(). Get the inversion for a seventh chord showing different roots >>> dim7 = chord.Chord('B4 D5 F5 A-5 C6 E6 G6') >>> dim7.inversion() 0 >>> dim7.inversion(testRoot=pitch.Pitch('D5')) 6 >>> dim7.inversion('six-four') Traceback (most recent call last): music21.chord.ChordException: Inversion must be an integer, got: Chords without pitches or otherwise impossible chords return -1, indicating no normal inversion. >>> chord.Chord().inversion(testRoot=pitch.Pitch('C5')) -1 For Harmony subclasses, this method does not check to see if the inversion is reasonable according to the figure provided. see :meth:`~music21.harmony.ChordSymbol.inversionIsValid` for checker method on ChordSymbolObjects. If only two pitches given, an inversion is still returned, often as if it were a triad: >>> chord.Chord('C4 G4').inversion() 0 >>> chord.Chord('G4 C5').inversion() 2 If transposeOnSet is False then setting the inversion simply sets the value to be returned later, which might be useful for cases where the chords are poorly spelled, or there is an added note. * Changed in v8: deal with chords without pitches ''' if not self.pitches: return -1 if testRoot is not None: rootPitch = testRoot else: rootPitch = self.root() if newInversion is not None: try: int_newInversion = int(newInversion) except (ValueError, TypeError): raise ChordException(f'Inversion must be an integer, got: {type(newInversion)}') self._setInversion(int_newInversion, rootPitch, transposeOnSet) return None elif ('inversion' not in self._overrides and find) or testRoot is not None: try: if rootPitch is None or self.bass() is None: return -1 except ChordException: raise ChordException('Not a normal inversion') # can this be run? return self._findInversion(rootPitch) elif 'inversion' in self._overrides: return self._overrides['inversion'] else: return -1 def _setInversion( self, newInversion: int, rootPitch: pitch.Pitch, transposeOnSet: bool, ) -> None: ''' Helper function for inversion(int) ''' if transposeOnSet is False: self._overrides['inversion'] = newInversion return # could have set bass or root externally numberOfRunsBeforeCrashing = len(self.pitches) + 2 soughtInversion = newInversion if 'inversion' in self._overrides: del self._overrides['inversion'] if 'bass' in self._overrides: # bass might have been overridden for a different octave del self._overrides['bass'] currentInversion = self.inversion(find=True) while currentInversion != soughtInversion and numberOfRunsBeforeCrashing > 0: currentMaxMidi = max(self.pitches).ps tempBassPitch = self.bass() while tempBassPitch.ps < currentMaxMidi: if tempBassPitch.octave is not None: tempBassPitch.octave += 1 else: tempBassPitch.octave = tempBassPitch.implicitOctave + 1 # housekeeping for next loop tests self.clearCache() currentInversion = self.inversion(find=True) numberOfRunsBeforeCrashing -= 1 if numberOfRunsBeforeCrashing == 0: raise ChordException('Could not invert chord: inversion may not exist') self.sortAscending(inPlace=True) def _findInversion(self, rootPitch: pitch.Pitch) -> int: ''' Helper function for .inversion() ''' # bassNote = self.bass() # do all interval calculations with bassNote being one octave below root note tempBassPitch = copy.deepcopy(self.bass()) tempBassPitch.octave = 1 tempRootPitch = copy.deepcopy(rootPitch) tempRootPitch.octave = 2 bassToRoot = interval.notesToGeneric(tempBassPitch, tempRootPitch).simpleDirected # print('bassToRoot', bassToRoot) if bassToRoot == 1: inv = 0 elif bassToRoot == 6: # triads inv = 1 elif bassToRoot == 4: # triads inv = 2 elif bassToRoot == 2: # sevenths inv = 3 elif bassToRoot == 7: # ninths inv = 4 elif bassToRoot == 5: # eleventh inv = 5 elif bassToRoot == 3: # thirteenth inv = 6 else: inv = -1 # no longer raise an exception if not normal inversion # is this cache worth it? or more trouble than it's worth self._cache['inversion'] = inv return inv def inversionName(self) -> int|None: ''' Returns an integer representing the common abbreviation for the inversion the chord is in. If chord is not in a common inversion, returns None. Third inversion sevenths return 42 not 2. >>> a = chord.Chord(['G3', 'B3', 'F3', 'D3']) >>> a.inversionName() 43 ''' inv: int # pylint requires this outside of the "try" to avoid "invalid-sequence-index" try: inv = self.inversion() except ChordException: return None if inv == -1: return None seventhMapping = [7, 65, 43, 42] triadMapping = [53, 6, 64] if self.isSeventh() or self.seventh is not None: if 0 <= inv <= 3: return seventhMapping[inv] else: raise ChordException(f'Not a normal inversion for a seventh: {inv!r}') elif self.isTriad(): if 0 <= inv <= 2: return triadMapping[inv] else: raise ChordException(f'Not a normal inversion for a triad: {inv!r}') else: raise ChordException('Not a triad or Seventh, cannot determine inversion.') def inversionText(self) -> str: ''' A helper method to return a readable inversion text (with capitalization) for a chord: >>> chord.Chord('C4 E4 G4').inversionText() 'Root Position' >>> chord.Chord('E4 G4 C5').inversionText() 'First Inversion' >>> chord.Chord('B-3 C4 E4 G4').inversionText() 'Third Inversion' >>> chord.Chord().inversionText() 'Unknown Position' ''' UNKNOWN = 'Unknown Position' inv: int # pylint requires this outside of the "try" to avoid "invalid-sequence-index" try: inv = self.inversion() except ChordException: return UNKNOWN if inv == -1: return UNKNOWN if inv == 0: return 'Root Position' return common.numberTools.ordinals[inv] + ' Inversion' def isAugmentedSixth(self, *, permitAnyInversion=False): ''' returns True if the chord is an Augmented 6th chord in normal inversion. (that is, in first inversion for Italian and German and second for French and Swiss) >>> c = chord.Chord(['A-3', 'C4', 'E-4', 'F#4']) >>> c.isAugmentedSixth() True Spelling matters >>> c.pitches[3].getEnharmonic(inPlace=True) >>> c >>> c.isAugmentedSixth() False Italian: >>> c = chord.Chord(['A-3', 'C4', 'F#4']) >>> c.isAugmentedSixth() True If `permitAnyInversion` is True then any inversion is allowed. ''' # cardinality is just used to speed up the call to avoid checking multiple augmented # 6ths on a triad, etc. The fact that Ab C F# Gb will have cardinality of 3 # but fail isItalianAugmentedSixth is not a problem. cardinality = self.pitchClassCardinality if cardinality == 3 and self.isItalianAugmentedSixth(permitAnyInversion=permitAnyInversion): return True if cardinality == 4: if self.isFrenchAugmentedSixth(permitAnyInversion=permitAnyInversion): return True elif self.isGermanAugmentedSixth(permitAnyInversion=permitAnyInversion): return True elif self.isSwissAugmentedSixth(permitAnyInversion=permitAnyInversion): return True return False @cacheMethod def isAugmentedTriad(self): ''' Returns True if chord is an Augmented Triad, that is, if it contains only notes that are either in unison with the root, a major third above the root, or an augmented fifth above the root. Additionally, the Chord must contain at least one of each third and fifth above the root. The chord might not seem to need to be spelled correctly since incorrectly spelled Augmented Triads are usually augmented triads in some other inversion (e.g. C-E-Ab is a second-inversion augmented triad; C-Fb-Ab is in first inversion). However, B#-Fb-Ab does return False as it is not a stack of two major thirds in any inversion. Returns False if is not an augmented triad. >>> c = chord.Chord(['C4', 'E4', 'G#4']) >>> c.isAugmentedTriad() True >>> c = chord.Chord(['C4', 'E4', 'G4']) >>> c.isAugmentedTriad() False Other spellings will give other roots! >>> c = chord.Chord(['C4', 'E4', 'A-4']) >>> c.isAugmentedTriad() True >>> c.root() >>> c = chord.Chord(['C4', 'F-4', 'A-4']) >>> c.isAugmentedTriad() True >>> c = chord.Chord(['B#4', 'F-4', 'A-4']) >>> c.isAugmentedTriad() False >>> chord.Chord().isAugmentedTriad() False ''' return self._checkTriadType((3, 12, 0), 4, 8) @cacheMethod def isConsonant(self): # noinspection PyShadowingNames ''' Returns True if the chord is: * one pitch (always consonant) * two pitches: uses :meth:`~music21.interval.Interval.isConsonant()` , which checks if the interval is a major or minor third or sixth or perfect fifth. * three pitches: if chord is a major or minor triad not in second inversion. These rules define all common-practice consonances (and earlier back to about 1300 all imperfect consonances) >>> c1 = chord.Chord(['C3', 'E4', 'G5']) >>> c1.isConsonant() True >>> c2 = chord.Chord(['G3', 'E-4', 'C5']) >>> c2.isConsonant() False >>> c3 = chord.Chord(['F2', 'A2', 'C3', 'E-3']) >>> c3.isConsonant() False >>> c4 = chord.Chord(['C1', 'G1', 'C2', 'G2', 'C3', 'G3']) >>> c4.isConsonant() True >>> c5 = chord.Chord(['G1', 'C2', 'G2', 'C3', 'G3']) >>> c5.isConsonant() False >>> c6 = chord.Chord(['F#']) >>> c6.isConsonant() True >>> c7 = chord.Chord(['C1', 'C#1', 'D-1']) >>> c7.isConsonant() False Spelling does matter: >>> c8 = chord.Chord(['D-4', 'G#4']) >>> c8.isConsonant() False >>> c9 = chord.Chord(['D3', 'A2', 'D2', 'D2', 'A4']) >>> c9.isConsonant() True >>> c10 = chord.Chord(['D3', 'A2', 'D2', 'D2', 'A1']) >>> c10.isConsonant() False >>> c11 = chord.Chord(['F3', 'D4', 'A4']) >>> c11.isConsonant() True >>> c12 = chord.Chord(['F3', 'D4', 'A4', 'E#4']) >>> c12.isConsonant() False OMIT_FROM_DOCS Weird things used to happen when some notes have octaves and some don't: >>> c13 = chord.Chord(['A4', 'B4', 'A']) >>> c14 = c13.removeRedundantPitchNames(inPlace=False) >>> c14 >>> i14 = interval.Interval(c14.pitches[0], c14.pitches[1]) >>> i14 >>> i14.isConsonant() False >>> c13.isConsonant() False ''' c2 = self.removeRedundantPitchNames(inPlace=False) if len(c2.pitches) == 1: return True elif len(c2.pitches) == 2: c3 = self.closedPosition() # to get from lowest to highest for P4 protection c4 = c3.removeRedundantPitches(inPlace=False) i = interval.Interval(c4.pitches[0], c4.pitches[1]) return i.isConsonant() elif len(c2.pitches) == 3: if ((self.isMajorTriad() is True or self.isMinorTriad() is True) and (self.inversion() != 2)): return True else: return False else: return False @cacheMethod def isDiminishedSeventh(self): ''' Returns True if chord is a Diminished Seventh, that is, if it contains only notes that are either in unison with the root, a minor third above the root, a diminished fifth, or a minor seventh above the root. Additionally, must contain at least one of each third and fifth above the root. Chord must be spelled correctly. Otherwise returns false. >>> a = chord.Chord(['c', 'e-', 'g-', 'b--']) >>> a.isDiminishedSeventh() True >>> chord.Chord().isDiminishedSeventh() False ''' return self.isSeventhOfType((0, 3, 6, 9)) def isSeventhOfType(self, intervalArray): ''' Returns True if chord is a seventh chord of a particular type as specified by intervalArray. For instance `.isDiminishedSeventh()` is just a thin wrapper around `.isSeventhOfType([0, 3, 6, 9])` and `isDominantSeventh()` has intervalArray([0, 4, 7, 10]) intervalArray can be any iterable. Though it checks on intervalArray, it does make sure that it is a seventh chord, not D--, D##, G, B- >>> chord.Chord('C E G B-').isSeventhOfType((0, 4, 7, 10)) True >>> chord.Chord('C E G B-').isSeventhOfType((0, 3, 7, 10)) False >>> chord.Chord('D-- D## G B-').isSeventhOfType((0, 4, 7, 10)) False ''' if not self.isSeventh(): return False root = self.root() for thisPitch in self.pitches: thisInterval = interval.Interval(root, thisPitch) if thisInterval.chromatic.mod12 not in intervalArray: return False return True @cacheMethod def isDiminishedTriad(self) -> bool: ''' Returns True if chord is a Diminished Triad, that is, if it contains only notes that are either in unison with the root, a minor third above the root, or a diminished fifth above the root. Additionally, must contain at least one of each third and fifth above the root. Chord must be spelled correctly. Otherwise returns false. >>> cChord = chord.Chord(['C', 'E-', 'G-']) >>> cChord.isDiminishedTriad() True >>> other = chord.Chord(['C', 'E-', 'F#']) >>> other.isDiminishedTriad() False OMIT_FROM_DOCS >>> chord.Chord().isDiminishedTriad() False >>> other = chord.Chord(['C', 'E-', 'F#', 'G-']) >>> other.isDiminishedTriad() False This is in an OMIT section ''' return self._checkTriadType((3, 10, 0), 3, 6) @cacheMethod def isDominantSeventh(self) -> bool: ''' Returns True if chord is a Dominant Seventh, that is, if it contains only notes that are either in unison with the root, a major third above the root, a perfect fifth, or a major seventh above the root. Additionally, must contain at least one of each third and fifth above the root. Chord must be spelled correctly. Otherwise returns false. >>> a = chord.Chord(['b', 'g', 'd', 'f']) >>> a.isDominantSeventh() True >>> chord.Chord().isDominantSeventh() False >>> c2 = chord.Chord('C4 E4 G4 A#4') >>> c2.isDominantSeventh() False ''' return self.isSeventhOfType((0, 4, 7, 10)) @cacheMethod def isFalseDiminishedSeventh(self) -> bool: ''' Returns True if chord is a Diminished Seventh, that is, if it contains only notes that are either in unison with the root, a minor third above the root, a diminished fifth, or a diminished seventh above the root. Additionally, must contain at least one of each third and fifth above the root. Chord MAY BE SPELLED INCORRECTLY. Otherwise returns False. >>> c = chord.Chord('C D# G- A') >>> c.isFalseDiminishedSeventh() True >>> chord.Chord().isFalseDiminishedSeventh() False >>> chord.Chord('C4 E4 G4').isFalseDiminishedSeventh() False Correctly spelled diminished seventh chords are also false diminished sevenths. >>> chord.Chord('C4 E-4 G-4 B--4').isFalseDiminishedSeventh() True ''' return self.chordTablesAddress[:3] == (4, 28, 0) def isFrenchAugmentedSixth(self, *, permitAnyInversion=False) -> bool: ''' Returns True if the chord is a French augmented sixth chord (flat 6th scale degree in bass, tonic, second scale degree, and raised 4th). N.B. The root() method of music21.chord.Chord determines the root based on the note with the most thirds above it. However, under this definition, a 1st-inversion french augmented sixth chord resembles a second inversion chord, not the first inversion subdominant chord it is based upon. We fix this by adjusting the root. First, however, we check to see if the chord is in second inversion to begin with, otherwise it is not a Fr+6 chord. This is to avoid ChordException errors. >>> fr6a = chord.Chord(['A-3', 'C4', 'D4', 'F#4']) >>> fr6a.isFrenchAugmentedSixth() True Spelling matters: >>> fr6b = chord.Chord(['A-3', 'C4', 'D4', 'G-4']) >>> fr6b.isFrenchAugmentedSixth() False >>> fr6b = chord.Chord(['A-3', 'C4', 'E--4', 'F#4']) >>> fr6b.isFrenchAugmentedSixth() False Inversion matters: >>> fr6c = chord.Chord(['C4', 'D4', 'F#4', 'A-4']) >>> fr6c.isFrenchAugmentedSixth() False Unless `permitAnyInversion` is True >>> fr6c.isFrenchAugmentedSixth(permitAnyInversion=True) True * Changed in v7: `permitAnyInversion` added OMIT_FROM_DOCS >>> chord.Chord().isFrenchAugmentedSixth() False >>> fr6d = chord.Chord(['A-3', 'C-4', 'D4', 'F#4']) >>> fr6d.isFrenchAugmentedSixth() False ''' return self._isAugmentedSixthHelper( (4, 25, 0), 2, permitAnyInversion, [('M3', 'm-6'), ('d5', 'A-4'), ('m7', 'M-2')] ) def isGermanAugmentedSixth(self, *, permitAnyInversion=False) -> bool: ''' Returns True if the chord is a German augmented sixth chord (flat 6th scale degree in bass, tonic, flat third scale degree, and raised 4th). >>> gr6a = chord.Chord(['A-3', 'C4', 'E-4', 'F#4']) >>> gr6a.isGermanAugmentedSixth() True Spelling matters (see isSwissAugmentedSixth) >>> gr6b = chord.Chord(['A-3', 'C4', 'D#4', 'F#4']) >>> gr6b.isGermanAugmentedSixth() False Inversion matters: >>> gr6c = chord.Chord(['C4', 'E-4', 'F#4', 'A-4']) >>> gr6c.isGermanAugmentedSixth() False unless `permitAnyInversion` is True: >>> gr6c.isGermanAugmentedSixth(permitAnyInversion=True) True * Changed in v7: `permitAnyInversion` added OMIT_FROM_DOCS >>> chord.Chord().isGermanAugmentedSixth() False >>> gr6d = chord.Chord(['A-3', 'C-4', 'E-4', 'F#4']) >>> gr6d.isGermanAugmentedSixth() False ''' return self._isAugmentedSixthHelper( (4, 27, -1), 1, permitAnyInversion, [('d3', 'A-6'), ('d5', 'A-4'), ('d7', 'A-2')] ) @cacheMethod def isHalfDiminishedSeventh(self) -> bool: ''' Returns True if chord is a Half Diminished Seventh, that is, if it contains only notes that are either in unison with the root, a minor third above the root, a diminished fifth, or a major seventh above the root. Additionally, must contain at least one of each third, fifth, and seventh above the root. Chord must be spelled correctly. Otherwise returns false. >>> c1 = chord.Chord(['C4', 'E-4', 'G-4', 'B-4']) >>> c1.isHalfDiminishedSeventh() True Incorrectly spelled chords are not considered half-diminished sevenths >>> c2 = chord.Chord(['C4', 'E-4', 'G-4', 'A#4']) >>> c2.isHalfDiminishedSeventh() False Nor are incomplete chords >>> c3 = chord.Chord(['C4', 'G-4', 'B-4']) >>> c3.isHalfDiminishedSeventh() False >>> chord.Chord().isHalfDiminishedSeventh() False ''' return self.isSeventhOfType((0, 3, 6, 10)) @cacheMethod def isIncompleteMajorTriad(self) -> bool: ''' Returns True if the chord is an incomplete Major triad, or, essentially, a dyad of root and major third >>> c1 = chord.Chord(['C4', 'E3']) >>> c1.isMajorTriad() False >>> c1.isIncompleteMajorTriad() True Note that complete major triads return False: >>> c2 = chord.Chord(['C4', 'E3', 'G5']) >>> c2.isIncompleteMajorTriad() False Remember, MAJOR Triad: >>> c3 = chord.Chord(['C4', 'E-3']) >>> c3.isIncompleteMajorTriad() False Must be spelled properly >>> c1 = chord.Chord(['C4', 'F-4']) >>> c1.isIncompleteMajorTriad() False Empty Chords return False >>> chord.Chord().isIncompleteMajorTriad() False OMIT_FROM_DOCS Swap the two notes: >>> c1 = chord.Chord(['C####4', 'E----4']) >>> c1.isIncompleteMajorTriad() False ''' if self.chordTablesAddress[:2] != (2, 4): return False third = self.third if third is None: return False for thisPitch in self.pitches: thisInterval = interval.Interval(self.root(), thisPitch) if thisInterval.chromatic.mod12 not in (0, 4): return False return True @cacheMethod def isIncompleteMinorTriad(self) -> bool: ''' returns True if the chord is an incomplete Minor triad, or, essentially, a dyad of root and minor third >>> c1 = chord.Chord(['C4', 'E-3']) >>> c1.isMinorTriad() False >>> c1.isIncompleteMinorTriad() True >>> c2 = chord.Chord(['C4', 'E-3', 'G5']) >>> c2.isIncompleteMinorTriad() False OMIT_FROM_DOCS >>> c3 = chord.Chord(['C4', 'E4']) >>> c3.isIncompleteMinorTriad() False >>> c3 = chord.Chord(['C4', 'D#4']) >>> c3.isIncompleteMinorTriad() False >>> c3 = chord.Chord(['C###4', 'E---4']) >>> c3.isIncompleteMinorTriad() False >>> chord.Chord().isIncompleteMinorTriad() False ''' if self.chordTablesAddress[:2] != (2, 3): return False third = self.third if third is None: return False for thisPitch in self.pitches: thisInterval = interval.Interval(self.root(), thisPitch) if thisInterval.chromatic.mod12 not in (0, 3): return False return True def isItalianAugmentedSixth(self, *, restrictDoublings=False, permitAnyInversion=False) -> bool: ''' Returns True if the chord is a properly spelled Italian augmented sixth chord in first inversion. Otherwise returns False. If restrictDoublings is set to True then only the tonic may be doubled. >>> c1 = chord.Chord(['A-4', 'C5', 'F#6']) >>> c1.isItalianAugmentedSixth() True Spelling matters: >>> c2 = chord.Chord(['A-4', 'C5', 'G-6']) >>> c2.isItalianAugmentedSixth() False So does inversion: >>> c3 = chord.Chord(['F#4', 'C5', 'A-6']) >>> c3.isItalianAugmentedSixth() False >>> c4 = chord.Chord(['C5', 'A-5', 'F#6']) >>> c4.isItalianAugmentedSixth() False If inversions don't matter to you, add `permitAnyInversion=True`: >>> c3.isItalianAugmentedSixth(permitAnyInversion=True) True >>> c4.isItalianAugmentedSixth(permitAnyInversion=True) True If doubling rules are turned on then only the tonic can be doubled: >>> c4 = chord.Chord(['A-4', 'C5', 'F#6', 'C6', 'C7']) >>> c4.isItalianAugmentedSixth(restrictDoublings=True) True >>> c5 = chord.Chord(['A-4', 'C5', 'F#6', 'C5', 'F#7']) >>> c5.isItalianAugmentedSixth(restrictDoublings=True) False >>> c5.isItalianAugmentedSixth(restrictDoublings=False) True * Changed in v7: `restrictDoublings` is keyword only. Added `permitAnyInversion`. ''' aug6check = self._isAugmentedSixthHelper( (3, 8, 1), 1, permitAnyInversion, [('d3', 'A-6'), ('d5', 'A-4')] ) if not aug6check: return False if restrictDoublings: root = self.root() third = self.third fifth = self.fifth if not fifth: return False # only the tonic (that is, fifth) can be doubled for p in self.pitches: if p.name == fifth.name: continue if p is not third and p is not root: return False return True def _isAugmentedSixthHelper( self, chordTableAddress: tuple[int, int, int], requiredInversion: int, permitAnyInversion: bool, intervalsCheck: list[tuple[str, str]], ) -> bool: ''' Helper method for simplifying checking Italian, German, etc. Augmented Sixth chords ''' if self.chordTablesAddress[:3] != chordTableAddress: return False if self.hasAnyEnharmonicSpelledPitches(): return False # Chord must be in first inversion. try: if not permitAnyInversion and self.inversion() != requiredInversion: return False except ChordException: return False root = self.root() third = self.third if third is None: return False thirdInterval = interval.Interval(root, third) if thirdInterval.directedSimpleName not in intervalsCheck[0]: return False fifth = self.fifth if fifth is None: return False fifthInterval = interval.Interval(root, fifth) if fifthInterval.directedSimpleName not in intervalsCheck[1]: return False if len(intervalsCheck) < 3: return True seventh = self.seventh if seventh is None: return False seventhInterval = interval.Interval(root, seventh) if seventhInterval.directedSimpleName not in intervalsCheck[2]: return False return True def _checkTriadType(self, chordAddress, thirdSemitones, fifthSemitones): ''' Helper method for `isMajorTriad`, `isMinorTriad`, `isDiminishedTriad`, and `isAugmentedTriad` that checks the chordAddress first, then the number of semitones the third should be and fifth. Deals with strange corner cases like C, E###, G--- not being a major triad, as quickly as possible. ''' # chordTablesAddress takes only 39 microseconds compared to 220 for # rest of routine, so might as well short-circuit for false if self.chordTablesAddress[:3] != chordAddress: return False if not self.isTriad(): return False if self.hasAnyEnharmonicSpelledPitches(): return False # these are cached, and guaranteed to be non-None by isTriad() third = self.third fifth = self.fifth root = self.root() rootPitchClass = root.pitchClass thirdInterval = (third.pitchClass - rootPitchClass) % 12 if thirdInterval != thirdSemitones: return False fifthInterval = (fifth.pitchClass - rootPitchClass) % 12 if fifthInterval != fifthSemitones: return False return True @cacheMethod def isMajorTriad(self): ''' Returns True if chord is a Major Triad, that is, if it contains only notes that are either in unison with the root, a major third above the root, or a perfect fifth above the root. Additionally, must contain at least one of each third and fifth above the root. Chord must be spelled correctly. Otherwise returns false. Example: >>> cChord = chord.Chord(['C', 'E', 'G']) >>> other = chord.Chord(['C', 'G']) >>> cChord.isMajorTriad() True >>> other.isMajorTriad() False Notice that the proper spelling of notes is crucial >>> chord.Chord(['B-', 'D', 'F']).isMajorTriad() True >>> chord.Chord(['A#', 'D', 'F']).isMajorTriad() False (See: :meth:`~music21.chord.Chord.forteClassTn` to catch this case; major triads in the forte system are 3-11B no matter how they are spelled.) >>> chord.Chord(['A#', 'D', 'F']).forteClassTn == '3-11B' True OMIT_FROM_DOCS Strange chords like [C,E###,G---] used to return True. E### = G and G--- = E, so the chord is found to be a major triad, even though it should not be. This bug is now fixed. >>> chord.Chord(['C', 'E###', 'G---']).isMajorTriad() False >>> chord.Chord(['C', 'E', 'G', 'E###', 'G---']).isMajorTriad() False >>> chord.Chord().isMajorTriad() False ''' return self._checkTriadType((3, 11, -1), 4, 7) @cacheMethod def isMinorTriad(self): ''' Returns True if chord is a Minor Triad, that is, if it contains only notes that are either in unison with the root, a minor third above the root, or a perfect fifth above the root. Additionally, must contain at least one of each third and fifth above the root. Chord must be spelled correctly. Otherwise returns false. Example: >>> cChord = chord.Chord(['C', 'E-', 'G']) >>> cChord.isMinorTriad() True >>> other = chord.Chord(['C', 'E', 'G']) >>> other.isMinorTriad() False OMIT_FROM_DOCS >>> chord.Chord().isMinorTriad() False ''' return self._checkTriadType((3, 11, 1), 3, 7) def isTranspositionallySymmetrical(self, *, requireIntervallicEvenness=False) -> bool: ''' Returns True if the Chord is symmetrical under transposition and False otherwise. A pitch-class-based way of looking at this, is can all the pitch classes be transposed up some number of semitones 1-11 and end up with the same pitch-classes. Like the dyad F-B can have each note transposed up 6 semitones and get another B-F = F-B dyad. A tonally-focused way of looking at this would be to ask, "Are we unable to distinguish root position vs. some inversion of the basic chord by ear alone?" For instance, we can see (visually) that C-Eb-Gb-Bbb is a diminished-seventh chord in root position, while Eb-Gb-Bbb-C is a diminished-seventh in first inversion. But if the chord were heard in isolation it would not be possible to tell the inversion at all, since diminished-sevenths are transpositionally symmetrical. With either way of looking at it, there are fourteen set classes of 2-10 pitch classes have this property, including the augmented triad: >>> chord.Chord('C E G#').isTranspositionallySymmetrical() True But the major triad is not transpositionally symmetrical: >>> chord.Chord('C E G').isTranspositionallySymmetrical() False The whole-tone scale and the Petrushka chord are both transpositionally symmetrical: >>> wholeToneAsChord = chord.Chord('C D E F# G# B- C') >>> wholeToneAsChord.isTranspositionallySymmetrical() True >>> petrushka = chord.Chord([0, 1, 3, 6, 7, 9]) >>> petrushka.isTranspositionallySymmetrical() True If `requireIntervallicEvenness` is True then only chords that also have even spacing / evenly divide the octave are considered transpositionally symmetrical. The normal cases are the F-B (06) dyad, the augmented triad, the diminished-seventh chord, and the whole-tone scale collection: >>> wholeToneAsChord.isTranspositionallySymmetrical(requireIntervallicEvenness=True) True >>> petrushka.isTranspositionallySymmetrical(requireIntervallicEvenness=True) False Note that complements of these chords (except the whole-tone collection) are not transpositionally symmetrical if `requireIntervallicEvenness` is required: >>> chord.Chord([0, 4, 8]).isTranspositionallySymmetrical(requireIntervallicEvenness=True) True >>> chord.Chord([1, 2, 3, 5, 6, 7, 9, 10, 11]).isTranspositionallySymmetrical( ... requireIntervallicEvenness=True) False Empty chords and the total aggregate cannot have their inversion determined by ear alone. So they are `True` with or without `requireIntervallicEvenness`. >>> chord.Chord().isTranspositionallySymmetrical() True >>> chord.Chord(list(range(12))).isTranspositionallySymmetrical() True Monads (single-note "chords") cannot be transposed 1-11 semitones to recreate themselves, so they return `False` by default: >>> chord.Chord('C').isTranspositionallySymmetrical() False But they are the only case where `requireIntervallicEvenness` actually switches from `False` to `True`, because they do evenly divide the octave. >>> chord.Chord('C').isTranspositionallySymmetrical(requireIntervallicEvenness=True) True 11-note chords return `False` in either case: >>> chord.Chord(list(range(11))).isTranspositionallySymmetrical() False ''' if not self._notes: return True address = self.chordTablesAddress if address.cardinality == 1: return requireIntervallicEvenness lookup = (address.cardinality, address.forteClass) if lookup in ( (2, 6), # 06 -- omitted by Straus # noqa: E241 (3, 12), # augmented triad (4, 28), # diminished seventh chord (6, 35), # whole-tone scale (12, 1), # total aggregate. ): return True if not requireIntervallicEvenness and lookup in ( (4, 9), # 0167 # noqa: E241 (4, 25), # 0268 (6, 7), # 012678 # noqa: E241 (6, 20), # "Hexatonic scale" 014589 (6, 30), # Petrushka chord 013679 (8, 9), # 01236789 # noqa: E241 (8, 25), # 0124678T (8, 28), # octatonic scale (9, 12), # complement to augmented triad (10, 6), # complement to 06 ): return True else: return False @cacheMethod def isSeventh(self): ''' Returns True if chord contains at least one of each of Third, Fifth, and Seventh, and every note in the chord is a Third, Fifth, or Seventh, such that there are no repeated scale degrees (ex: E and E-). Else return false. Example: >>> cChord = chord.Chord(['C', 'E', 'G', 'B']) >>> cChord.isSeventh() True >>> other = chord.Chord(['C', 'D', 'E', 'F', 'G', 'B']) >>> other.isSeventh() False OMIT_FROM_DOCS >>> chord.Chord().isSeventh() False ''' uniquePitchNames = set(self.pitchNames) if len(uniquePitchNames) != 4: return False if self.third is None: return False if self.fifth is None: return False if self.seventh is None: return False return True @cacheMethod def isNinth(self): ''' Returns True if chord contains at least one of each of Third, Fifth, Seventh, and Ninth and every note in the chord is a Third, Fifth, Seventh, or Ninth, such that there are no repeated scale degrees (ex: E and E-). Else return false. Example: >>> cChord = chord.Chord(['C', 'E', 'G', 'B', 'D']) >>> cChord.isNinth() True >>> other = chord.Chord(['C', 'E', 'F', 'G', 'B']) >>> other.isNinth() False OMIT_FROM_DOCS >>> chord.Chord().isNinth() False >>> chord.Chord('C C# C## C### C###').isNinth() False >>> chord.Chord('C C# E B D').isNinth() False >>> chord.Chord('C E G C- D').isNinth() False ''' uniquePitchNames = set(self.pitchNames) if len(uniquePitchNames) != 5: return False if self.third is None: return False if self.fifth is None: return False if self.seventh is None: return False try: return bool(self.getChordStep(2)) except ChordException: # pragma: no cover # probably not reachable, since self.third would have caught the same # exception and returned False return False def isSwissAugmentedSixth(self, *, permitAnyInversion=False): ''' Returns true if it is a respelled German augmented 6th chord with sharp 2 instead of flat 3. This chord has many names, Swiss Augmented Sixth, Alsatian Chord, English A6, Norwegian, etc. as well as doubly-augmented sixth, which is a bit of a misnomer since it is the 4th that is doubly augmented, not the sixth. >>> chord.Chord('A-4 C5 D#5 F#6').isSwissAugmentedSixth() True Respelled as a German Augmented Sixth does not count: >>> chord.Chord('A-4 C5 E-5 F#6').isSwissAugmentedSixth() False Inversions matter: >>> ch3 = chord.Chord('F#4 D#5 C6 A-6') >>> ch3.isSwissAugmentedSixth() False unless `permitAnyInversion` is given: >>> ch3.isSwissAugmentedSixth(permitAnyInversion=True) True * Changed in v7: `permitAnyInversion` added ''' return self._isAugmentedSixthHelper( (4, 27, -1), 2, permitAnyInversion, [('m3', 'M-6'), ('dd5', 'AA-4'), ('d7', 'A-2')] ) @cacheMethod def isTriad(self) -> bool: ''' Returns True if this Chord is a triad of some sort. It could even be a rather exotic triad so long as the chord contains at least one Third and one Fifth and all notes have the same name as one of the three notes. Note: only returns True if triad is spelled correctly. Note the difference of "containsTriad" vs. "isTriad": A dominant-seventh chord is NOT a triad, but it contains two triads. >>> cChord = chord.Chord(['C4', 'E4', 'A4']) >>> cChord.isTriad() True >>> other = chord.Chord(['C', 'D', 'E', 'F', 'G']) >>> other.isTriad() False >>> incorrectlySpelled = chord.Chord(['C', 'D#', 'G']) >>> incorrectlySpelled.isTriad() False >>> incorrectlySpelled.pitches[1].getEnharmonic(inPlace=True) >>> incorrectlySpelled >>> incorrectlySpelled.isTriad() True OMIT_FROM_DOCS >>> chord.Chord().isTriad() False >>> chord.Chord('C4 E4 G4 B#4').isTriad() False ''' uniquePitchNames = set(self.pitchNames) if len(uniquePitchNames) == 3 and self.third and self.fifth: return True return False def removeRedundantPitches(self, *, inPlace=False): ''' Remove all but one instance of a pitch that appears twice. It removes based on the name of the note and the octave, so the same note name in two different octaves is retained. If `inPlace` is True, a copy is not made and a list of deleted pitches is returned; otherwise make and return a copy. >>> c1 = chord.Chord(['c2', 'e3', 'g4', 'e3']) >>> c1 >>> removedList = c1.removeRedundantPitches(inPlace=True) >>> c1 >>> removedList [] >>> c1.forteClass '3-11B' >>> c2 = chord.Chord(['c2', 'e3', 'g4', 'c5']) >>> c2c = c2.removeRedundantPitches(inPlace=False) >>> c2c It is a known bug that because pitch.nameWithOctave gives the same value for B-flat in octave 1 as B-natural in octave negative 1, negative octaves can screw up this method. With all the things left to do for music21, it doesn't seem a bug worth squashing at this moment, but FYI: >>> p1 = pitch.Pitch('B-') >>> p1.octave = 1 >>> p2 = pitch.Pitch('B') >>> p2.octave = -1 >>> c3 = chord.Chord([p1, p2]) >>> removedPitches = c3.removeRedundantPitches(inPlace=True) >>> c3.pitches (,) >>> c3.pitches[0].name 'B-' >>> c3.pitches[0].octave 1 >>> removedPitches [] >>> removedPitches[0].name 'B' >>> removedPitches[0].octave -1 The first pitch survives: >>> c3.pitches[0] is p1 True >>> c3.pitches[0] is p2 False * Changed in v6: inPlace defaults to False. ''' return self._removePitchByRedundantAttribute('nameWithOctave', inPlace=inPlace) def removeRedundantPitchClasses(self, *, inPlace=False): ''' Remove all but the FIRST instance of a pitch class with more than one instance of that pitch class. If `inPlace` is True, a copy is not made and a list of deleted pitches is returned; otherwise a copy is made and that copy is returned. >>> c1 = chord.Chord(['c2', 'e3', 'g4', 'e3']) >>> removed = c1.removeRedundantPitchClasses(inPlace=True) >>> c1.pitches (, , ) >>> c2 = chord.Chord(['c5', 'e3', 'g4', 'c2', 'e3', 'f-4']) >>> removed = c2.removeRedundantPitchClasses(inPlace=True) >>> c2.pitches (, , ) * Changed in v6: inPlace defaults to False. ''' return self._removePitchByRedundantAttribute('pitchClass', inPlace=inPlace) def removeRedundantPitchNames(self, *, inPlace=False): ''' Remove all but the FIRST instance of a pitch class with more than one instance of that pitch name regardless of octave (but note that spelling matters, so that in the example, the F-flat stays even though there is already an E.) If `inPlace` is True, a copy is not made and a list of deleted pitches is returned; otherwise a copy is made and that copy is returned. >>> c2 = chord.Chord(['c5', 'e3', 'g4', 'c2', 'e3', 'f-4']) >>> c2 >>> rem = c2.removeRedundantPitchNames(inPlace=True) >>> c2 >>> rem [, ] * Changed in v6: inPlace defaults to False. ''' return self._removePitchByRedundantAttribute('name', inPlace=inPlace) @overload def root(self, newroot: None = None, *, find: bool|None = None ) -> pitch.Pitch: ... @overload def root(self, newroot: str|pitch.Pitch|note.Note, *, find: bool|None = None ) -> None: ... def root(self, newroot: None|str|pitch.Pitch|note.Note = None, *, find: bool|None = None ) -> pitch.Pitch|None: # noinspection PyShadowingNames ''' Returns the root of the chord. Or if given a Pitch as the newroot will override the algorithm and always return that Pitch. >>> cmaj = chord.Chord(['E3', 'C4', 'G5']) >>> cmaj.root() Examples: >>> cmaj = chord.Chord(['E', 'G', 'C']) >>> cmaj.root() For some chords we make an exception. For instance, take this chord in B-flat minor: >>> aDim7no3rd = chord.Chord(['A3', 'E-4', 'G4']) It could be considered a type of E-flat 11 chord with a 3rd, but no 5th, 7th, or 9th, in 5th inversion. That doesn't make sense, so we should call it an A dim 7th chord with no 3rd. >>> aDim7no3rd.root() >>> aDim7no3rdInv = chord.Chord(['E-3', 'A4', 'G4']) >>> aDim7no3rdInv.root() The root of a 13th chord (which could be any chord in any inversion) is designed to be the bass: >>> chord.Chord('F3 A3 C4 E-4 G-4 B4 D5').root() Multiple pitches in different octaves do not interfere with root. >>> lotsOfNotes = chord.Chord(['E3', 'C4', 'G4', 'B-4', 'E5', 'G5']) >>> r = lotsOfNotes.root() >>> r >>> r is lotsOfNotes.pitches[1] True Setting of a root may happen for a number of reasons, such as in the case where music21's idea of a root differs from the interpreter's. To specify the root directly, pass the pitch to the root function: >>> cSus4 = chord.Chord('C4 F4 G4') >>> cSus4.root() # considered by music21 to be an F9 chord in 2nd inversion Change it to be a Csus4: >>> cSus4.root('C4') >>> cSus4.root() Note that if passing in a string as the root, the root is set to a pitch in the chord if possible. >>> cSus4.root() is cSus4.pitches[0] True You might also want to supply an "implied root." For instance, some people call a diminished seventh chord (generally viio7) a dominant chord with an omitted root (Vo9) -- here we will specify the root to be a note not in the chord: >>> vo9 = chord.Chord(['B3', 'D4', 'F4', 'A-4']) >>> vo9.root() >>> vo9.root(pitch.Pitch('G3')) >>> vo9.root() When setting a root, the pitches of the chord are left untouched: >>> [p.nameWithOctave for p in vo9.pitches] ['B3', 'D4', 'F4', 'A-4'] By default, this method uses an algorithm to find the root among the chord's pitches, if no root has been previously specified. If a root has been explicitly specified, as in the Csus4 chord above, it can be returned to the original root() by setting find explicitly to True: >>> cSus4.root(find=True) Subsequent calls without find=True have also removed the overridden root: >>> cSus4.root() If for some reason you do not want the root-finding algorithm to be run (for instance, checking to see if an overridden root has been specified) set find=False. "None" will be returned if no root has been specified. >>> c = chord.Chord(['E3', 'G3', 'B4']) >>> print(c.root(find=False)) None Chord symbols, for instance, have their root already specified on construction: >>> d = harmony.ChordSymbol('CM/E') >>> d.root(find=False) There is no need to set find=False in this case, however, the algorithm will skip the slow part of finding the root if it has been specified (or already found and no pitches have changed). A chord with no pitches has no root and raises a ChordException. >>> chord.Chord().root() Traceback (most recent call last): music21.chord.ChordException: no pitches in chord * Changed in v5.2: `find` is a keyword-only parameter, `newroot` finds `Pitch` in `Chord` ''' # None value for find indicates: return override if overridden, cache if cached # or find new value if neither is the case. if newroot: newroot_pitch: pitch.Pitch if isinstance(newroot, str): newroot = common.cleanedFlatNotation(newroot) newroot_pitch = pitch.Pitch(newroot) elif isinstance(newroot, note.Note): newroot_pitch = newroot.pitch elif isinstance(newroot, pitch.Pitch): newroot_pitch = newroot else: raise ValueError(f'Cannot find a Pitch in {newroot!r}') # try to set newroot to be a pitch in the chord if possible foundRootInChord = False for p in self.pitches: # first by identity if newroot_pitch is p: foundRootInChord = True break if not foundRootInChord: for p in self.pitches: # then by name with octave if p.nameWithOctave == newroot_pitch.nameWithOctave: newroot_pitch = p foundRootInChord = True break if not foundRootInChord: # finally by name for p in self.pitches: if p.name == newroot_pitch.name: newroot_pitch = p break self._overrides['root'] = newroot_pitch self._cache['root'] = newroot_pitch if 'inversion' in self._cache: del self._cache['inversion'] # reset inversion if root changes return None elif find is True: if 'root' in self._overrides: del self._overrides['root'] if 'inversion' in self._cache: del self._cache['inversion'] self._cache['root'] = self._findRoot() return self._cache['root'] elif ('root' not in self._overrides) and find is not False: if 'root' in self._cache: return self._cache['root'] else: self._cache['root'] = self._findRoot() return self._cache['root'] elif 'root' in self._overrides: return self._overrides['root'] else: return None @overload def semiClosedPosition( self: _ChordType, *, forceOctave, inPlace: t.Literal[True], leaveRedundantPitches=False ) -> None: return None @overload def semiClosedPosition( self: _ChordType, *, forceOctave=None, inPlace: t.Literal[False] = False, leaveRedundantPitches=False ) -> _ChordType: return self def semiClosedPosition( self: _ChordType, *, forceOctave: int|None = None, inPlace: t.Literal[True]|t.Literal[False] = False, leaveRedundantPitches: bool = False ) -> None|_ChordType: # noinspection PyShadowingNames ''' Similar to :meth:`~music21.chord.Chord.ClosedPosition` in that it moves everything within an octave EXCEPT if there's already a pitch at that step, then it puts it up an octave. It's a very useful display standard for dense post-tonal chords. >>> c1 = chord.Chord(['C3', 'E5', 'C#6', 'E-7', 'G8', 'C9', 'E#9']) >>> c2 = c1.semiClosedPosition(inPlace=False) >>> c2 `leaveRedundantPitches` still works, and gives them a new octave! >>> c3 = c1.semiClosedPosition( ... inPlace=False, ... leaveRedundantPitches=True, ... ) >>> c3 of course `forceOctave` still works, as does `inPlace=True`. >>> c1.semiClosedPosition( ... forceOctave=2, ... inPlace=True, ... leaveRedundantPitches=True, ... ) >>> c1 ''' c2 = self.closedPosition(forceOctave=forceOctave, inPlace=inPlace, leaveRedundantPitches=leaveRedundantPitches) if inPlace is True: c2 = self if t.TYPE_CHECKING: from music21.stream import Stream assert isinstance(c2, Stream) # startOctave = c2.bass().octave remainingPitches = copy.copy(c2.pitches) # no deepcopy needed while remainingPitches: usedSteps = [] newRemainingPitches = [] for i, p in enumerate(remainingPitches): if p.step not in usedSteps: usedSteps.append(p.step) else: p.octave += 1 newRemainingPitches.append(p) remainingPitches = newRemainingPitches c2.clearCache() c2.sortAscending(inPlace=True) if inPlace is False: return c2 def semitonesFromChordStep(self, chordStep, testRoot=None): ''' Returns the number of semitones (mod12) above the root that the chordStep lies (i.e., 3 = third of the chord; 5 = fifth, etc.) if one exists. Or None if it does not exist. You can optionally specify a note.Note object to try as the root. It does not change the Chord.root object. We use these methods to figure out what the root of the triad is. Currently, there is a bug that in the case of a triply diminished third (e.g., "c" => "e----"), this function will incorrectly claim no third exists. Perhaps this should be construed as a feature. In the case of chords such as C, E-, E, semitonesFromChordStep(3) will return the number for the first third, in this case 3. It will not return 4, nor a list object (3, 4). You probably do not want to be using tonal chord manipulation functions on chords such as these anyway. Check for such cases with chord.hasAnyRepeatedDiatonicNote first. Tools with the expression "chordStep" in them refer to the diatonic third, fifth, etc., of the chord. They have little to do with the scale degree of the scale or key that the chord is embedded within. See "chord.scaleDegrees" for this functionality. >>> cChord = chord.Chord(['E3', 'C4', 'G5']) >>> cChord.semitonesFromChordStep(3) # distance from C to E 4 >>> cChord.semitonesFromChordStep(5) # C to G 7 Omitted chordSteps return None >>> print(cChord.semitonesFromChordStep(6)) None Note that the routine returns the semitones to the FIRST third. This chord has two thirds, C and C# >>> aChord = chord.Chord(['a2', 'c4', 'c#5', 'e#7']) >>> aChord.semitonesFromChordStep(3) 3 >>> aChord.semitonesFromChordStep(5) 8 >>> print(aChord.semitonesFromChordStep(2)) None Test whether this strange chord gets the B# as 0 semitones: >>> c = chord.Chord(['C4', 'E4', 'G4', 'B#4']) >>> c.semitonesFromChordStep(7) 0 If testRoot is set to a Pitch object then that note is used as the root of the chord regardless of anything else that might be considered. A-minor: 1st inversion. >>> aMin = chord.Chord(['C4', 'E4', 'A4']) >>> aMin.semitonesFromChordStep(3) 3 >>> aMin.semitonesFromChordStep(5) 7 C6 chord, jazz like, root position: >>> cPitch = pitch.Pitch('C4') >>> c6 = aMin # renaming for clarity >>> c6.semitonesFromChordStep(3, testRoot = cPitch) 4 >>> c6.semitonesFromChordStep(5, testRoot = cPitch) is None True >>> c6.semitonesFromChordStep(6, testRoot = cPitch) 9 ''' tempInt = self.intervalFromChordStep(chordStep, testRoot=testRoot) if tempInt is None: return None else: return tempInt.chromatic.mod12 def setColor(self, value, pitchTarget=None): ''' Set color for specific pitch. >>> c = chord.Chord('C4 E4 G4') >>> c.setColor('red', 'C4') >>> c['0.style.color'] 'red' >>> c.setColor('blue') # set for whole chord >>> c.style.color 'blue' >>> c['E4.style.color'] 'blue' >>> c.setColor('red', 'C9') Traceback (most recent call last): music21.chord.ChordException: the given pitch is not in the Chord: C9 ''' # assign to base if pitchTarget is None and self._notes: # Pylint going crazy here self.style.color = value # pylint: disable=attribute-defined-outside-init for n in self._notes: n.style.color = value # pylint: disable=attribute-defined-outside-init return elif isinstance(pitchTarget, str): pitchTarget = pitch.Pitch(pitchTarget) match = False for d in self._notes: if d.pitch is pitchTarget: d.style.color = value match = True break if not match: # look at equality of value for d in self._notes: if d.pitch == pitchTarget: d.style.color = value match = True break if not match: raise ChordException( f'the given pitch is not in the Chord: {pitchTarget}') def setNotehead(self, nh, pitchTarget): ''' Given a notehead attribute as a string and a pitch object in this Chord, set the notehead attribute of that pitch to the value of that notehead. Valid notehead type names are found in note.noteheadTypeNames (see below): >>> for noteheadType in note.noteheadTypeNames: ... noteheadType ... 'arrow down' 'arrow up' 'back slashed' 'circle dot' 'circle-x' 'circled' 'cluster' 'cross' 'diamond' 'do' 'fa' 'fa up' 'inverted triangle' 'la' 'left triangle' 'mi' 'none' 'normal' 'other' 're' 'rectangle' 'slash' 'slashed' 'so' 'square' 'ti' 'triangle' 'x' >>> n1 = note.Note('D4') >>> n2 = note.Note('G4') >>> c1 = chord.Chord([n1, n2]) >>> c1.setNotehead('diamond', c1.pitches[1]) # just to g >>> c1.getNotehead(c1.pitches[1]) 'diamond' >>> c1.getNotehead(c1.pitches[0]) 'normal' If a chord has two of the same pitch, but each associated with a different notehead, then object equality must be used to distinguish between the two. >>> c2 = chord.Chord(['D4', 'D4']) >>> secondD4 = c2.pitches[1] >>> c2.setNotehead('diamond', secondD4) >>> for i in [0, 1]: ... c2.getNotehead(c2.pitches[i]) ... 'normal' 'diamond' By default, assigns to first pitch: >>> c3 = chord.Chord('C3 F4') >>> c3.setNotehead('slash', None) >>> c3['0.notehead'] 'slash' Less safe to match by string, but possible: >>> c3.setNotehead('so', 'F4') >>> c3['1.notehead'] 'so' Error: >>> c3.setNotehead('so', 'G4') Traceback (most recent call last): music21.chord.ChordException: the given pitch is not in the Chord: G4 ''' # assign to first pitch by default if pitchTarget is None and self._notes: pitchTarget = self._notes[0].pitch elif isinstance(pitchTarget, str): pitchTarget = pitch.Pitch(pitchTarget) match = False for d in self._notes: if d.pitch is pitchTarget: d.notehead = nh match = True break if not match: for d in self._notes: if d.pitch == pitchTarget: d.notehead = nh match = True break if not match: raise ChordException(f'the given pitch is not in the Chord: {pitchTarget}') def setNoteheadFill(self, nh, pitchTarget): ''' Given a noteheadFill attribute as a string (or False) and a pitch object in this Chord, set the noteheadFill attribute of that pitch to the value of that notehead. Valid noteheadFill names are True, False, None (default) >>> n1 = note.Note('D4') >>> n2 = note.Note('G4') >>> c1 = chord.Chord([n1, n2]) >>> c1.setNoteheadFill(False, c1.pitches[1]) # just to g >>> c1.getNoteheadFill(c1.pitches[1]) False >>> c1.getNoteheadFill(c1.pitches[0]) is None True If a chord has two of the same pitch, but each associated with a different notehead, then object equality must be used to distinguish between the two. >>> c2 = chord.Chord(['D4', 'D4']) >>> secondD4 = c2.pitches[1] >>> c2.setNoteheadFill(False, secondD4) >>> for i in [0, 1]: ... print(c2.getNoteheadFill(c2.pitches[i])) ... None False By default, assigns to first pitch: >>> c3 = chord.Chord('C3 F4') >>> c3.setNoteheadFill(False, None) >>> c3['0.noteheadFill'] False Less safe to match by string, but possible: >>> c3.setNoteheadFill(True, 'F4') >>> c3['1.noteheadFill'] True Error: >>> c3.setNoteheadFill(True, 'G4') Traceback (most recent call last): music21.chord.ChordException: the given pitch is not in the Chord: G4 ''' # assign to first pitch by default if pitchTarget is None and self._notes: pitchTarget = self._notes[0].pitch elif isinstance(pitchTarget, str): pitchTarget = pitch.Pitch(pitchTarget) match = False for d in self._notes: if d.pitch is pitchTarget: d.noteheadFill = nh match = True break if not match: for d in self._notes: if d.pitch == pitchTarget: d.noteheadFill = nh match = True break if not match: raise ChordException(f'the given pitch is not in the Chord: {pitchTarget}') def setStemDirection(self, stem, pitchTarget): ''' Given a stem attribute as a string and a pitch object in this Chord, set the stem attribute of that pitch to the value of that stem. Valid stem directions are found note.stemDirectionNames (see below). >>> for name in note.stemDirectionNames: ... name ... 'double' 'down' 'noStem' 'none' 'unspecified' 'up' >>> n1 = note.Note('D4') >>> n2 = note.Note('G4') >>> c1 = chord.Chord([n1, n2]) >>> c1.setStemDirection('double', c1.pitches[1]) # just to g >>> c1.getStemDirection(c1.pitches[1]) 'double' >>> c1.getStemDirection(c1.pitches[0]) 'unspecified' If a chord has two of the same pitch, but each associated with a different stem, then object equality must be used to distinguish between the two. >>> c2 = chord.Chord(['D4', 'D4']) >>> secondD4 = c2.pitches[1] >>> c2.setStemDirection('double', secondD4) >>> for i in [0, 1]: ... print(c2.getStemDirection(c2.pitches[i])) ... unspecified double By default, assigns to first pitch: >>> c3 = chord.Chord('C3 F4') >>> c3.setStemDirection('down', None) >>> c3['0.stemDirection'] 'down' Less safe to match by string, but possible: >>> c3.setStemDirection('down', 'F4') >>> c3['1.stemDirection'] 'down' Error: >>> c3.setStemDirection('up', 'G4') Traceback (most recent call last): music21.chord.ChordException: the given pitch is not in the Chord: G4 ''' if pitchTarget is None and self._notes: pitchTarget = self._notes[0].pitch # first is default elif isinstance(pitchTarget, str): pitchTarget = pitch.Pitch(pitchTarget) match = False for d in self._notes: if d.pitch is pitchTarget: d.stemDirection = stem match = True break if not match: for d in self._notes: if d.pitch == pitchTarget: d.stemDirection = stem match = True break if not match: raise ChordException( f'the given pitch is not in the Chord: {pitchTarget}') def setTie(self, tieObjOrStr: tie.Tie|str, pitchTarget): ''' Given a tie object (or a tie type string) and a pitch or Note in this Chord, set the pitch's tie attribute in this chord to that tie type. >>> c1 = chord.Chord(['d3', 'e-4', 'b-4']) >>> t1 = tie.Tie('start') >>> c1.setTie(t1, 'b-4') # or it can be done with a pitch.Pitch object >>> c1.getTie(c1.pitches[2]) is t1 True Setting a tie with a chord with the same pitch twice requires getting the exact pitch object out to be sure which one: >>> c2 = chord.Chord(['D4', 'D4']) >>> secondD4 = c2.pitches[1] >>> c2.setTie('start', secondD4) >>> for i in [0, 1]: ... print(c2.getTie(c2.pitches[i])) ... None >>> c3 = chord.Chord('C3 F4') >>> c3.setTie('start', None) >>> c3.getTie(c3.pitches[0]) Less safe to match by string, because there might be multiple pitches with the same name in the chord, but possible: >>> c4 = chord.Chord('D4 F#4') >>> c4.setTie('start', 'F#4') >>> c4.getTie('F#4') Setting a tie on a note not in the chord is an error: >>> c3.setTie('stop', 'G4') Traceback (most recent call last): music21.chord.ChordException: the given pitch is not in the Chord: G4 ''' if pitchTarget is None and self._notes: # if no pitch pitchTarget = self._notes[0].pitch elif isinstance(pitchTarget, str): pitchTarget = pitch.Pitch(pitchTarget) tieObj: tie.Tie if isinstance(tieObjOrStr, str): tieObj = tie.Tie(tieObjOrStr) else: tieObj = tieObjOrStr match = False for d in self._notes: if d.pitch is pitchTarget or d is pitchTarget: # compare by obj id first d.tie = tieObj match = True break if not match: # more loose comparison: by == for d in self._notes: if pitchTarget in (d, d.pitch): d.tie = tieObj match = True break if not match: raise ChordException( f'the given pitch is not in the Chord: {pitchTarget}') def setVolume(self, vol: volume.Volume, target: str|note.Note|pitch.Pitch): ''' Set the :class:`~music21.volume.Volume` object of a specific Pitch. * Changed in v8: after appearing in ChordBase in v7, it has been properly moved back to Chord itself. The ability to change just the first note's volume has been removed. Use `Chord().volume = vol` to change the volume for a whole chord. ''' # assign to first pitch by default if isinstance(target, str): pitchTarget = pitch.Pitch(target) elif isinstance(target, note.Note): pitchTarget = target.pitch elif isinstance(target, pitch.Pitch): pitchTarget = target else: raise ValueError(f'Cannot setVolume on target {target!r}') match = False for d in self._notes: if d.pitch is pitchTarget or d.pitch == pitchTarget: vol.client = self # noinspection PyArgumentList d._setVolume(vol, setClient=False) match = True break if not match: raise ChordException(f'the given pitch is not in the Chord: {pitchTarget}') def simplifyEnharmonics(self, *, inPlace=False, keyContext=None): ''' Calls `pitch.simplifyMultipleEnharmonics` on the pitches of the chord. Simplifies the enharmonics in the sense of making a more logical chord. Note below that E# is added there because C# major is simpler than C# F G#. >>> c = chord.Chord('C# F G#') >>> c.pitches (, , ) >>> c.simplifyEnharmonics(inPlace=True) >>> c.pitches (, , ) If `keyContext` is provided the enharmonics are simplified based on the supplied Key or KeySignature. >>> c.simplifyEnharmonics(inPlace=True, keyContext=key.Key('A-')) >>> c.pitches (, , ) ''' if inPlace: returnObj = self else: returnObj = copy.deepcopy(self) pitches = pitch.simplifyMultipleEnharmonics(self.pitches, keyContext=keyContext) for i in range(len(pitches)): returnObj._notes[i].pitch = pitches[i] if inPlace is False: return returnObj def sortAscending(self, *, inPlace=False): return self.sortDiatonicAscending(inPlace=inPlace) def sortChromaticAscending(self): ''' Same as sortAscending but notes are sorted by midi number, so F## sorts above G-. ''' newChord = copy.deepcopy(self) # tempChordNotes = newChord.pitches newChord._notes.sort(key=lambda x: x.pitch.ps) return newChord def sortDiatonicAscending(self, *, inPlace=False): ''' The notes are sorted by :attr:`~music21.pitch.Pitch.diatonicNoteNum` or vertical position on a grand staff (so F## sorts below G-). Notes that are the identical diatonicNoteNum are further sorted by :attr:`~music21.pitch.Pitch.ps` (midi numbers that accommodate floats). We return a new Chord object with the notes arranged from lowest to highest (unless inPlace=True) >>> cMajUnsorted = chord.Chord(['E4', 'C4', 'G4']) >>> cMajSorted = cMajUnsorted.sortDiatonicAscending() >>> cMajSorted.pitches[0].name 'C' >>> c2 = chord.Chord(['E4', 'C4', 'G4']) >>> c2.sortDiatonicAscending(inPlace=True) >>> c2 >>> sameDNN = chord.Chord(['F#4', 'F4']) >>> sameDNN.sortDiatonicAscending() * Changed in v6: if inPlace is True do not return anything. ''' if inPlace: if self._cache.get('isSortedAscendingDiatonic', False): return None returnObj = self self.clearCache() else: # cache is not copied to the new item. returnObj = copy.deepcopy(self) returnObj._notes.sort(key=lambda x: (x.pitch.diatonicNoteNum, x.pitch.ps)) returnObj._cache['isSortedAscendingDiatonic'] = True if not inPlace: return returnObj def sortFrequencyAscending(self): ''' Same as above, but uses a note's frequency to determine height; so that C# would be below D- in 1/4-comma meantone, equal in equal temperament, but below it in (most) just intonation types. ''' newChord = copy.deepcopy(self) newChord._notes.sort(key=lambda x: x.pitch.frequency) return newChord def transpose(self, value, *, inPlace=False): ''' Transpose the Chord by the user-provided value. If the value is an integer, the transposition is treated in half steps and enharmonics might be simplified (not done yet). If the value is a string, any Interval string specification can be provided. If inPlace is set to True (default = False) then the original chord is changed. Otherwise a new Chord is returned. We take a three-note chord (G, A, C#) and transpose it up a minor third, getting the chord B-flat, C, E. >>> a = chord.Chord(['g4', 'a3', 'c#6']) >>> b = a.transpose('m3') >>> b Here we create the interval object first (rather than giving a string) and specify transposing down six semitones, instead of saying A-4. >>> aInterval = interval.Interval(-6) >>> b = a.transpose(aInterval) >>> b If `inPlace` is True then rather than returning a new chord, the chord itself is changed. >>> a.transpose(aInterval, inPlace=True) >>> a ''' if hasattr(value, 'diatonic'): # it is an Interval class intervalObj = value else: # try to process intervalObj = interval.Interval(value) if not inPlace: post = copy.deepcopy(self) else: post = self # call transpose on component Notes for n in post._notes: n.transpose(intervalObj, inPlace=True) # for p in post.pitches: # # we are either operating on self or a copy; always use inPlace # p.transpose(intervalObj, inPlace=True) # # pitches.append(intervalObj.transposePitch(p)) if not inPlace: return post else: return None # PUBLIC PROPERTIES # # see https://github.com/python/mypy/issues/1362 @property # type: ignore @cacheMethod def chordTablesAddress(self): ''' Return a four-element ChordTableAddress that represents that raw data location for information on the set class interpretation of this Chord as well as the original pitchClass The data format is a Forte set class cardinality, index number, and inversion status (where 0 is invariant, and -1 and 1 represent inverted or not, respectively). >>> c = chord.Chord(['D4', 'F#4', 'B-4']) >>> c.chordTablesAddress ChordTableAddress(cardinality=3, forteClass=12, inversion=0, pcOriginal=2) >>> c = chord.Chord('G#2 A2 D3 G3') >>> c.chordTablesAddress ChordTableAddress(cardinality=4, forteClass=6, inversion=0, pcOriginal=2) This method caches the result so that it does not need to be looked up again. One change from chord.tables.seekChordTablesAddress: the empty chord returns a special address instead of raising an exception: >>> chord.Chord().chordTablesAddress ChordTableAddress(cardinality=0, forteClass=0, inversion=0, pcOriginal=0) ''' try: return tables.seekChordTablesAddress(self) except tables.ChordTablesException: return tables.ChordTableAddress(0, 0, 0, 0) @property # type: ignore @cacheMethod def commonName(self) -> str: ''' Return the most common name associated with this Chord as a string. Checks some common enharmonic equivalents. >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.commonName 'minor triad' >>> c2 = chord.Chord(['c', 'e', 'g']) >>> c2.commonName 'major triad' >>> c2b = chord.Chord(['c', 'f-', 'g']) >>> c2b.commonName 'enharmonic equivalent to major triad' >>> c3 = chord.Chord(['c', 'd-', 'e', 'f#']) >>> c3.commonName 'all-interval tetrachord' Chords with no common names just return the Forte Class >>> c3 = chord.Chord([0, 1, 2, 3, 4, 9]) >>> c3.commonName 'forte class 6-36B' Dominant seventh and German/Swiss sixths are distinguished >>> c4a = chord.Chord(['c', 'e', 'g', 'b-']) >>> c4a.commonName 'dominant seventh chord' >>> c4b = chord.Chord(['c', 'e', 'g', 'a#']) >>> c4b.commonName 'German augmented sixth chord' >>> c4c = chord.Chord(['c', 'e', 'f##', 'a#']) >>> c4c.commonName # some call it Alsacian or English 'Swiss augmented sixth chord' When in an unusual inversion, augmented sixth chords have their inversion added: >>> c4b = chord.Chord('A#3 C4 E4 G4') >>> c4b.commonName 'German augmented sixth chord in root position' Dyads are called by actual name: >>> dyad1 = chord.Chord('C E') >>> dyad1.commonName 'Major Third' >>> dyad2 = chord.Chord('C F-') >>> dyad2.commonName 'Diminished Fourth' Compound intervals are given in full if there are only two distinct pitches: >>> dyad1 = chord.Chord('C4 E5') >>> dyad1.commonName 'Major Tenth' But if there are more pitches, then the interval is given in a simpler form: >>> dyad1 = chord.Chord('C4 C5 E5 C6') >>> dyad1.commonName 'Major Third with octave doublings' If there are multiple enharmonics present just the simple number of semitones is returned. >>> dyad1 = chord.Chord('C4 E5 F-5 B#7') >>> dyad1.commonName '4 semitones' Special handling of one- and two-pitchClass chords: >>> gAlone = chord.Chord(['G4']) >>> gAlone.commonName 'note' >>> gAlone = chord.Chord('G4 G4') >>> gAlone.commonName 'unison' >>> gAlone = chord.Chord('G4 G5') >>> gAlone.commonName 'Perfect Octave' >>> gAlone = chord.Chord('G4 G6') >>> gAlone.commonName 'Perfect Double-octave' >>> gAlone = chord.Chord('G4 G5 G6') >>> gAlone.commonName 'multiple octaves' >>> gAlone = chord.Chord('F#4 G-4') >>> gAlone.commonName 'enharmonic unison' >>> chord.Chord().commonName 'empty chord' Microtonal chords all have the same commonName: >>> chord.Chord('C`4 D~4').commonName 'microtonal chord' Enharmonic equivalents to common sevenths and ninths are clarified: >>> chord.Chord('C4 E4 G4 A##4').commonName 'enharmonic equivalent to major seventh chord' >>> chord.Chord('C4 E-4 G4 A#4 D4').commonName 'enharmonic equivalent to minor-ninth chord' * Changed in v5.5: special cases for checking enharmonics in some cases * Changed in v6.5: better handling of 0-, 1-, and 2-pitchClass and microtonal chords. * Changed in v7: Inversions of augmented sixth-chords are specified. * Changed in v7.3: Enharmonic equivalents to common seventh and ninth chords are specified. OMIT_FROM_DOCS >>> chord.Chord('C E G C-').commonName 'enharmonic equivalent to major seventh chord' >>> chord.Chord('C E G B--').commonName 'enharmonic equivalent to minor seventh chord' >>> chord.Chord('C E G A').commonName 'minor seventh chord' ''' if any(not p.isTwelveTone() for p in self.pitches): return 'microtonal chord' cta = self.chordTablesAddress if cta.cardinality == 0: return 'empty chord' if cta.cardinality == 1: if len(self.pitches) == 1: return 'note' pitchNames = {p.name for p in self.pitches} pitchPSes = {p.ps for p in self.pitches} if len(pitchNames) == 1: if len(pitchPSes) == 1: return 'unison' if len(pitchPSes) == 2: return interval.Interval(self.pitches[0], self.pitches[1]).niceName else: return 'multiple octaves' if len(pitchPSes) == 1: return 'enharmonic unison' else: return 'enharmonic octaves' ctn = tables.addressToCommonNames(cta) if cta.cardinality == 2: pitchNames = {p.name for p in self.pitches} pitchPSes = {p.ps for p in self.pitches} # find two different pitchClasses p0 = self.pitches[0] p0pitchClass = p0.pitchClass p1: pitch.Pitch for p in self.pitches[1:]: if p.pitchClass != p0pitchClass: p1 = p break else: # pragma: no cover raise ChordException('Will never happen, just for typing.') relevantInterval = interval.Interval(p0, p1) if len(pitchNames) > 2: # C4 E4 B#4, etc. simpleUn = relevantInterval.chromatic.simpleUndirected plural = 's' if simpleUn != 1 else '' return f'{simpleUn} semitone{plural}' if len(pitchPSes) > 2: return relevantInterval.semiSimpleNiceName + ' with octave doublings' return interval.Interval(self.pitches[0], self.pitches[1]).niceName forteClass = self.forteClass # forteClassTn = self.forteClassTn def _isSeventhWithPerfectFifthsAboveRootAndThird(c: Chord) -> bool: ''' For testing minor-minor sevenths and major-major sevenths ''' if not c.isSeventh(): return False hypothetical_fifth = c.root().transpose('P5') if hypothetical_fifth.name not in c.pitchNames: return False third = c.third if not third: return False hypothetical_seventh = third.transpose('P5') if hypothetical_seventh.name not in c.pitchNames: return False return True enharmonicTests = { '3-11A': self.isMinorTriad, '3-11B': self.isMajorTriad, '3-10': self.isDiminishedTriad, '3-12': self.isAugmentedTriad, '4-27A': self.isHalfDiminishedSeventh, '4-28': self.isDiminishedSeventh, '5-27A': self.isNinth, # major-ninth '5-27B': self.isNinth, # minor-ninth '5-34': self.isNinth, # dominant-ninth } # special cases if forteClass == '4-27B': # dominant seventh OR German Aug 6 if self.isDominantSeventh(): return ctn[0] elif self.isGermanAugmentedSixth(): return ctn[2] elif self.isGermanAugmentedSixth(permitAnyInversion=True): return ctn[2] + ' in ' + self.inversionText().lower() elif self.isSwissAugmentedSixth(): return ctn[3] elif self.isSwissAugmentedSixth(permitAnyInversion=True): return ctn[3] + ' in ' + self.inversionText().lower() else: return 'enharmonic to ' + ctn[0] elif forteClass == '4-25': if self.isFrenchAugmentedSixth(): return ctn[1] elif self.isFrenchAugmentedSixth(permitAnyInversion=True): return ctn[1] + ' in ' + self.inversionText().lower() else: return ctn[0] elif forteClass == '3-8A': if self.isItalianAugmentedSixth(): return ctn[1] elif self.isItalianAugmentedSixth(permitAnyInversion=True): return ctn[1] + ' in ' + self.inversionText().lower() else: return ctn[0] elif forteClass in ('4-20', '4-26'): # minor seventh or major seventh chords, # but cannot just test isSeventh, as # that would permit C E G A## (A## as root) if _isSeventhWithPerfectFifthsAboveRootAndThird(self): return ctn[0] else: return 'enharmonic equivalent to ' + ctn[0] elif forteClass in enharmonicTests: out = ctn[0] test = enharmonicTests[forteClass] if not test(): out = 'enharmonic equivalent to ' + out return out if not ctn: return 'forte class ' + forteClass else: return ctn[0] @property def duration(self) -> Duration: # noinspection PyShadowingNames ''' Get or set the duration of this Chord as a Duration object. >>> c = chord.Chord(['a', 'c', 'e']) >>> c.duration Durations can be overridden after the fact: >>> d = duration.Duration() >>> d.quarterLength = 2 >>> c.duration = d >>> c.duration >>> c.duration == d True >>> c.duration is d True ''' d = t.cast(Duration|None, self._duration) # type: ignore if d is None and self._notes: # pitchZeroDuration = self._notes[0]['pitch'].duration pitchZeroDuration = self._notes[0].duration self._duration = pitchZeroDuration d_out = self._duration if t.TYPE_CHECKING: assert isinstance(d_out, Duration) return d_out @duration.setter def duration(self, durationObj: Duration): ''' Set a Duration object. ''' if isinstance(durationObj, Duration): self._duration = durationObj else: # need to permit Duration object assignment here raise ChordException(f'this must be a Duration object, not {durationObj}') @property # type: ignore @cacheMethod def fifth(self) -> pitch.Pitch|None: ''' Shortcut for getChordStep(5), but caches it and does not raise exceptions >>> cMaj1stInv = chord.Chord(['E3', 'C4', 'G5']) >>> cMaj1stInv.fifth >>> cMaj1stInv.fifth.midi 79 >>> chord.Chord('C4 D4').fifth is None True OMIT_FROM_DOCS >>> chord.Chord().fifth ''' try: return self.getChordStep(5) except ChordException: return None @property def forteClass(self): ''' Return the Forte set class name as a string. This assumes a Tn formation, where inversion distinctions are represented. (synonym: forteClassTn) >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.forteClass '3-11A' >>> c2 = chord.Chord(['c', 'e', 'g']) >>> c2.forteClass '3-11B' Empty chords return 'N/A' >>> chord.Chord().forteClass 'N/A' Non-twelve-tone chords return as if all microtones and non-twelve-tone accidentals are removed: >>> chord.Chord('c~4 d`4').forteClass '2-2' ''' try: return tables.addressToForteName(self.chordTablesAddress, 'tn') except tables.ChordTablesException: return 'N/A' @property def forteClassNumber(self): ''' Return the number of the Forte set class within the defined set group. That is, if the set is 3-11, this method returns 11. >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.forteClassNumber 11 >>> c2 = chord.Chord(['c', 'e', 'g']) >>> c2.forteClassNumber 11 ''' return self.chordTablesAddress.forteClass @property def forteClassTn(self): ''' A synonym for "forteClass" Return the Forte Tn set class name, where inversion distinctions are represented: >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.forteClass '3-11A' >>> c2 = chord.Chord(['c', 'e', 'g']) >>> c2.forteClassTn '3-11B' ''' return self.forteClass @property def forteClassTnI(self): ''' Return the Forte TnI class name, where inversion distinctions are not represented. >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.forteClassTnI '3-11' >>> c2 = chord.Chord(['c', 'e', 'g']) >>> c2.forteClassTnI '3-11' Empty chords return 'N/A' >>> chord.Chord().forteClassTnI 'N/A' Non-twelve-tone chords return as if all microtones and non-twelve-tone accidentals are removed: >>> chord.Chord('c~4 d`4').forteClassTnI '2-2' ''' try: return tables.addressToForteName(self.chordTablesAddress, 'tni') except tables.ChordTablesException: return 'N/A' @property def fullName(self): ''' Return the most complete representation of this Note, providing duration and pitch information. >>> c = chord.Chord(['D', 'F#', 'A']) >>> c.fullName 'Chord {D | F-sharp | A} Quarter' >>> chord.Chord(['d1', 'e4-', 'b3-'], quarterLength=2/3).fullName 'Chord {D in octave 1 | E-flat in octave 4 | B-flat in octave 3} Quarter Triplet (2/3 QL)' ''' msg = [] sub = [] for p in self.pitches: sub.append(f'{p.fullName}') msg.append('Chord') msg.append(' {' + (' | '.join(sub)) + '} ') msg.append(self.duration.fullName) return ''.join(msg) @property def hasZRelation(self): ''' Return True or False if the Chord has a Z-relation. >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.hasZRelation False >>> c2 = chord.Chord(['c', 'c#', 'e', 'f#']) >>> c2.hasZRelation # it is c, c#, e-, g True OMIT_FROM_DOCS >>> chord.Chord().hasZRelation False ''' try: post = tables.addressToZAddress(self.chordTablesAddress) except tables.ChordTablesException: return False # empty chords have no z-relations # environLocal.printDebug(['got post', post]) if post is not None: return True return False @property def intervalVector(self): ''' Return the interval vector for this Chord as a list of integers. >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.intervalVector [0, 0, 1, 1, 1, 0] >>> c2 = chord.Chord(['c', 'c#', 'e', 'f#']) >>> c2.intervalVector [1, 1, 1, 1, 1, 1] >>> c3 = chord.Chord(['c', 'c#', 'e-', 'g']) >>> c3.intervalVector [1, 1, 1, 1, 1, 1] OMIT_FROM_DOCS >>> chord.Chord().intervalVector [0, 0, 0, 0, 0, 0] ''' try: return list(tables.addressToIntervalVector(self.chordTablesAddress)) except tables.ChordTablesException: return [0, 0, 0, 0, 0, 0] @property def intervalVectorString(self): ''' Return the interval vector as a string representation. >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.intervalVectorString '<001110>' ''' return Chord.formatVectorString(self.intervalVector) @property def isPrimeFormInversion(self): ''' Return True or False if the Chord represents a set class inversion. >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.isPrimeFormInversion False >>> c2 = chord.Chord(['c', 'e', 'g']) >>> c2.isPrimeFormInversion True ''' if self.chordTablesAddress.inversion == -1: return True else: return False @property def multisetCardinality(self): ''' Return an integer representing the cardinality of the multiset, or the number of pitch values. >>> c1 = chord.Chord(['D4', 'A4', 'F#5', 'D6']) >>> c1.multisetCardinality 4 ''' return len(self.pitchClasses) @property def notes(self) -> tuple[note.Note, ...]: ''' Return a tuple (immutable) of the notes contained in the chord. Generally using .pitches or iterating over the chord is the best way to work with the components of a chord, but in unusual cases, a chord may, for instance, consist of notes with independent durations, volumes, or colors, or, more often, different tie statuses. `Chord` includes methods such as `.setTie()` for most of these features, but from time to time accessing all the `Note` objects as a tuple can be valuable. >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.duration.type = 'quarter' >>> c1Notes = c1.notes >>> c1Notes (, , ) Note that to set duration independently, a new Duration object needs to be created. Internal notes for Chords created from strings or pitches all share a Duration object. >>> c1.duration is c1Notes[0].duration True >>> c1Notes[1].duration is c1Notes[2].duration True >>> c1Notes[2].duration = duration.Duration('half') >>> c1.duration.type 'quarter' >>> c1[2].duration.type 'half' The property can also set the notes for a chord, but it must be set to an iterable of literal Note objects. >>> c1.notes = [note.Note('D#4'), note.Note('C#4')] >>> c1 Notice that the notes set this way are not sorted -- this is a property for power users who want complete control. Any incorrect assignment raises a TypeError: >>> c1.notes = 'C E G' Traceback (most recent call last): TypeError: notes must be set with an iterable >>> c1.notes = [pitch.Pitch('C'), pitch.Pitch('E')] Traceback (most recent call last): TypeError: every element of notes must be a note.Note object In case of an error, the previous notes are not changed (for this reason, `.notes` cannot take a generator expression). >>> c1 * New in v5.7 ''' return tuple(self._notes) @notes.setter def notes(self, newNotes: Iterable[note.Note]) -> None: ''' sets notes to an iterable of Note objects ''' if not common.isIterable(newNotes): raise TypeError('notes must be set with an iterable') if not all(isinstance(n, note.Note) for n in newNotes): raise TypeError('every element of notes must be a note.Note object') self._notes.clear() self.add(newNotes, runSort=False) @property # type: ignore @cacheMethod def normalOrder(self): ''' Return the normal order/normal form of the Chord represented as a list of integers: >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.normalOrder [0, 3, 7] >>> c2 = chord.Chord(['c', 'e', 'g']) >>> c2.normalOrder [0, 4, 7] >>> c3 = chord.Chord(['d', 'f#', 'a']) >>> c3.normalOrder [2, 6, 9] >>> c3 = chord.Chord(['B-4', 'D5', 'F5']) >>> c3.normalOrder [10, 2, 5] To get normalOrder transposed to PC 0, do this: >>> c3 = chord.Chord(['B-4', 'D5', 'F5']) >>> normalOrder = c3.normalOrder >>> firstPitch = normalOrder[0] >>> [(pc - firstPitch) % 12 for pc in normalOrder] [0, 4, 7] To get normalOrder formatted as a vectorString run .formatVectorString on it: >>> c3.normalOrder [10, 2, 5] >>> chord.Chord.formatVectorString(c3.normalOrder) '' (this is equivalent:) >>> c3.formatVectorString(c3.normalOrder) '' OMIT_FROM_DOCS These were giving problems before: >>> chord.Chord('G#2 A2 D3 G3').normalOrder [7, 8, 9, 2] >>> chord.Chord('G3 D4 A-4 A4 C5 E5').normalOrder [7, 8, 9, 0, 2, 4] >>> chord.Chord('E#3 A3 C#4').normalOrder [1, 5, 9] >>> chord.Chord('B5 G4 D5 E-5 D6').normalOrder [11, 2, 3, 7] >>> chord.Chord().normalOrder [] ''' cta = self.chordTablesAddress try: transposedNormalForm = tables.addressToTransposedNormalForm(cta) except tables.ChordTablesException: return [] orderedPCs = self.orderedPitchClasses mustBePresentPCs = set(orderedPCs) for transposeAmount in orderedPCs: possibleNormalOrder = [(pc + transposeAmount) % 12 for pc in transposedNormalForm] if set(possibleNormalOrder) == mustBePresentPCs: return possibleNormalOrder raise ChordException('Could not find a normalOrder for chord: ' + str(self.orderedPitchClassesString)) @property def normalOrderString(self): ''' Return the normal order/normal form of the Chord as a string representation. >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.normalOrder [0, 3, 7] >>> c1.normalOrderString '<037>' ''' return Chord.formatVectorString(self.normalOrder) def _unorderedPitchClasses(self) -> set[int]: ''' helper function for orderedPitchClasses but also routines like pitchClassCardinality which do not need sorting. Returns a set of ints ''' pcGroup = set() for p in self.pitches: pcGroup.add(p.pitchClass) return pcGroup @property def orderedPitchClasses(self) -> list[int]: ''' Return a list of pitch class integers, ordered form lowest to highest. >>> c1 = chord.Chord(['D4', 'A4', 'F#5', 'D6']) >>> c1.orderedPitchClasses [2, 6, 9] ''' return list(sorted(self._unorderedPitchClasses())) @property def orderedPitchClassesString(self) -> str: ''' Return a string representation of the pitch class values. >>> c1 = chord.Chord(['f#', 'e-', 'g']) >>> c1.orderedPitchClassesString '<367>' Redundancies are removed >>> c1 = chord.Chord(['f#', 'e-', 'e-', 'g']) >>> c1.orderedPitchClassesString '<367>' ''' return Chord.formatVectorString(self.orderedPitchClasses) @property def pitchClassCardinality(self) -> int: ''' Return the cardinality of pitch classes, or the number of unique pitch classes, in the Chord: >>> c1 = chord.Chord(['D4', 'A4', 'F#5', 'D6']) >>> c1.pitchClassCardinality 3 ''' return len(self._unorderedPitchClasses()) @property def pitchClasses(self) -> list[int]: ''' Return a list of all pitch classes in the chord as integers. Not sorted >>> c1 = chord.Chord(['D4', 'A4', 'F#5', 'D6']) >>> c1.pitchClasses [2, 9, 6, 2] ''' pcGroup = [] for p in self.pitches: pcGroup.append(p.pitchClass) return pcGroup @property def pitchNames(self) -> list[str]: ''' Return a list of Pitch names from each :class:`~music21.pitch.Pitch` object's :attr:`~music21.pitch.Pitch.name` attribute. >>> c = chord.Chord(['g#', 'd-']) >>> c.pitchNames ['G#', 'D-'] >>> c = chord.Chord('C4 E4 G4 C4') >>> c.pitchNames ['C', 'E', 'G', 'C'] >>> c.pitchNames = ['c2', 'g2'] >>> c.pitchNames ['C', 'G'] ''' return [d.pitch.name for d in self._notes] @pitchNames.setter def pitchNames(self, value): if common.isListLike(value): if isinstance(value[0], str): # only checking first self._notes = [] # clear for name in value: self._notes.append(note.Note(name)) else: raise ChordException( f'must provide a list containing a Pitch, not: {value}') else: raise ChordException(f'cannot set pitch name with provided object: {value}') self.clearCache() @property def pitchedCommonName(self) -> str: ''' Return a common name of this Chord including a pitch identifier, if possible: Most common chords will use the root as the pitch name and have it at the beginning: >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.pitchedCommonName 'C-minor triad' >>> c2 = chord.Chord(['c', 'e', 'g']) >>> c2.pitchedCommonName 'C-major triad' Because the hyphen is confusing w/ music21 flat notation, flats are displayed as "b": >>> c2a = chord.Chord('C-2 E-2 G-2') >>> c2a.pitchedCommonName 'Cb-major triad' Other forms might have the pitch elsewhere. Thus, this is a method for display, not for extracting information: >>> c3 = chord.Chord('A#2 D3 F3') >>> c3.pitchedCommonName 'enharmonic equivalent to major triad above A#' Note that in this case, the bass, not the root is used to determine the pitch name: >>> c4 = chord.Chord('D3 F3 A#3') >>> c4.pitchedCommonName 'enharmonic equivalent to major triad above D' >>> c5 = chord.Chord([1, 2, 3, 4, 5, 10]) >>> c5.pitchedCommonName 'forte class 6-36B above C#' >>> c4 = chord.Chord('D3 F3 A#3') >>> c4.pitchedCommonName 'enharmonic equivalent to major triad above D' A single pitch just returns that pitch name: >>> chord.Chord(['D3']).pitchedCommonName 'D' Unless there is more than one octave: >>> chord.Chord('D3 D4').pitchedCommonName 'Perfect Octave above D' >>> chord.Chord('D3 D4 D5').pitchedCommonName 'multiple octaves above D' Two different pitches give interval names: >>> chord.Chord('F3 C4').pitchedCommonName 'Perfect Fifth above F' Compound intervals are used unless there are multiple octaves: >>> chord.Chord('E-3 C5').pitchedCommonName 'Major Thirteenth above Eb' >>> chord.Chord('E-3 C5 C6').pitchedCommonName 'Major Sixth with octave doublings above Eb' These one-pitch-class and two-pitch-class chords with multiple enharmonics are unusual: >>> chord.Chord('D#3 E-3').pitchedCommonName 'enharmonic unison above D#' >>> chord.Chord('D#3 E-3 D#4').pitchedCommonName 'enharmonic octaves above D#' >>> chord.Chord('D#3 E-3 E3').pitchedCommonName '1 semitone above D#' >>> chord.Chord('D#3 E-3 F3 G--4').pitchedCommonName '2 semitones above D#' >>> chord.Chord().pitchedCommonName 'empty chord' * Changed in v5.5: octaves never included, flats are converted, special tools for enharmonics. * Changed in v6.5: special names for 0-, 1-, and 2-pitchClass chords. ''' nameStr = self.commonName if nameStr == 'empty chord': return nameStr if nameStr in ('note', 'unison'): return self.pitches[0].name if self.pitchClassCardinality <= 2 or ( 'enharmonic' in nameStr or 'forte class' in nameStr or ' semitone' in nameStr): # root detection gives weird results for pitchedCommonName bass = self.bass() bassName = bass.name.replace('-', 'b') return f'{nameStr} above {bassName}' else: try: root = self.root() except ChordException: # if a root cannot be found root = self.pitches[0] rootName = root.name.replace('-', 'b') return f'{rootName}-{nameStr}' @property def pitches(self) -> tuple[pitch.Pitch, ...]: ''' Get or set a list or tuple of all Pitch objects in this Chord. >>> c = chord.Chord(['C4', 'E4', 'G#4']) >>> c.pitches (, , ) >>> [p.midi for p in c.pitches] [60, 64, 68] >>> d = chord.Chord() >>> d.pitches = c.pitches >>> d.pitches (, , ) >>> c = chord.Chord(['C4', 'A4', 'E5']) >>> c.bass() >>> c.root() Note here that the list will be converted to a tuple: >>> c.pitches = ['C#4', 'A#4', 'E#5'] >>> c.pitches (, , ) Bass and root information is also changed. >>> c.bass() >>> c.root() ''' # noinspection PyTypeChecker pitches: tuple[pitch.Pitch, ...] = tuple(component.pitch for component in self._notes) return pitches @pitches.setter def pitches(self, value: Iterable[pitch.Pitch]) -> None: self._notes = [] self.clearCache() # TODO: individual ties are not being retained here for p in value: # assumes value is an iterable of pitches or something to pass to Note __init__ self._notes.append(note.Note(p)) @property def primeForm(self) -> list[int]: ''' Return a representation of the Chord as a prime-form list of pitch class integers: >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.primeForm [0, 3, 7] >>> c2 = chord.Chord(['c', 'e', 'g']) >>> c2.primeForm [0, 3, 7] OMIT_FROM_DOCS >>> chord.Chord().primeForm [] ''' try: return list(tables.addressToPrimeForm(self.chordTablesAddress)) except tables.ChordTablesException: return [] @property def primeFormString(self) -> str: ''' Return a representation of the Chord as a prime-form set class string. >>> c1 = chord.Chord(['c', 'e-', 'g']) >>> c1.primeFormString '<037>' >>> c1 = chord.Chord(['c', 'e', 'g']) >>> c1.primeFormString '<037>' ''' return Chord.formatVectorString(self.primeForm) @property # type: ignore @cacheMethod def quality(self): ''' Returns the quality of the underlying triad of a triad or seventh, either major, minor, diminished, augmented, or other: >>> a = chord.Chord(['a', 'c', 'e']) >>> a.quality 'minor' Inversions don't matter, nor do added tones so long as a root can be found: >>> a = chord.Chord(['f', 'b', 'd', 'g']) >>> a.quality 'major' >>> a = chord.Chord(['c', 'a-', 'e']) >>> a.quality 'augmented' >>> a = chord.Chord(['c', 'c#', 'd']) >>> a.quality 'other' Incomplete triads are returned as major or minor: >>> a = chord.Chord(['c', 'e-']) >>> a.quality 'minor' >>> a = chord.Chord(['e-', 'g']) >>> a.quality 'major' Chords that contain more than one triad return 'other' >>> chord.Chord('C C# E G').quality 'other' >>> chord.Chord('C E- E G').quality 'other' >>> chord.Chord('C E G- G').quality 'other' Note these two edge cases: >>> chord.Chord('C D E').quality # NB! Major 9th. 'major' >>> chord.Chord('C E--').quality 'other' Empty chords are definitely 'other': >>> chord.Chord().quality 'other' ''' try: third = self.semitonesFromChordStep(3) fifth = self.semitonesFromChordStep(5) except ChordException: return 'other' # environLocal.printDebug(['third, fifth', third, fifth]) if third is None: return 'other' elif self.hasRepeatedChordStep(1): return 'other' elif self.hasRepeatedChordStep(3): return 'other' elif fifth is None: if third == 4: return 'major' elif third == 3: return 'minor' else: return 'other' elif self.hasRepeatedChordStep(5): return 'other' elif fifth == 7 and third == 4: return 'major' elif fifth == 7 and third == 3: return 'minor' elif fifth == 8 and third == 4: return 'augmented' elif fifth == 6 and third == 3: return 'diminished' else: return 'other' @property def scaleDegrees(self): ''' Returns a list of two-element tuples for each pitch in the chord where the first element of the tuple is the scale degree as an int and the second is an Accidental object that specifies the alteration from the scale degree (could be None if the note is not part of the scale). It is easiest to see the utility of this method using a chord subclass, :class:`music21.roman.RomanNumeral`, but it is also callable from this Chord object if the Chord has a Key or Scale context set for it. >>> k = key.Key('f#') # 3-sharps minor >>> rn = roman.RomanNumeral('V', k) >>> rn.key >>> rn.pitches (, , ) >>> rn.scaleDegrees [(5, None), (7, ), (2, None)] >>> rn2 = roman.RomanNumeral('N6', k) >>> rn2.pitches (, , ) >>> rn2.scaleDegrees # N.B. -- natural form used for minor! [(4, None), (6, None), (2, )] As mentioned above, the property can also get its scale from context if the chord is embedded in a Stream. Let's create the same V in f#-minor again, but give it a context of c-sharp minor, and then c-minor instead: >>> chord1 = chord.Chord(['C#5', 'E#5', 'G#5']) >>> st1 = stream.Stream() >>> st1.append(key.Key('c#')) # c-sharp minor >>> st1.append(chord1) >>> chord1.scaleDegrees [(1, None), (3, ), (5, None)] >>> st2 = stream.Stream() >>> chord2 = chord.Chord(['C#5', 'E#5', 'G#5']) >>> st2.append(key.Key('c')) # c minor >>> st2.append(chord2) # same pitches as before gives different scaleDegrees >>> chord2.scaleDegrees [(1, ), (3, ), (5, )] >>> st3 = stream.Stream() >>> st3.append(key.Key('C')) # C major >>> chord2 = chord.Chord(['C4', 'C#4', 'D4', 'E-4', 'E4', 'F4']) # 1st 1/2 of chromatic >>> st3.append(chord2) >>> chord2.scaleDegrees [(1, None), (1, ), (2, None), (3, ), (3, None), (4, None)] If no context can be found, return `None`: >>> chord.Chord('C4 E4 G4').scaleDegrees is None True * Changed in v6.5: will return `None` if no context can be found: ''' from music21 import scale # roman numerals have this built in as the key attribute if hasattr(self, 'key') and self.key is not None: # pylint: disable=no-member # Key is a subclass of scale.DiatonicScale sc = self.key # pylint: disable=no-member else: sc = self.getContextByClass(scale.Scale, sortByCreationTime=True) if sc is None: return None degrees = [] for thisPitch in self.pitches: degree = sc.getScaleDegreeFromPitch( thisPitch, comparisonAttribute='step', direction=scale.Direction.DESCENDING, ) if degree is None: degrees.append((None, None)) else: actualPitch = sc.pitchFromDegree( degree, direction=scale.Direction.DESCENDING ) if actualPitch.name == thisPitch.name: degrees.append((degree, None)) else: actualPitch.octave = thisPitch.octave tupleKey = (degree, pitch.Accidental(int(thisPitch.ps - actualPitch.ps))) degrees.append(tupleKey) return degrees @property # type: ignore @cacheMethod def seventh(self): ''' Shortcut for getChordStep(7), but caches the value >>> bDim7_2ndInv = chord.Chord(['F2', 'A-3', 'B4', 'D5']) >>> bDim7_2ndInv.seventh Test whether this strange chord gets the B# not the C or something else: >>> c = chord.Chord(['C4', 'E4', 'G4', 'B#4']) >>> c.seventh * Changed in v6.5: return None on empty chords/errors OMIT_FROM_DOCS >>> chord.Chord().seventh ''' try: return self.getChordStep(7) except ChordException: return None @property # type: ignore @cacheMethod def third(self) -> pitch.Pitch|None: ''' Shortcut for getChordStep(3), but caches the value, and returns None on errors. >>> cMaj1stInv = chord.Chord(['E3', 'C4', 'G5']) >>> cMaj1stInv.third >>> cMaj1stInv.third.octave 3 * Changed in v6.5: return `None` on empty chords/errors OMIT_FROM_DOCS >>> chord.Chord().third ''' try: return self.getChordStep(3) except ChordException: return None def fromForteClass(notation: str|Sequence[int]) -> Chord: ''' Return a Chord given a Forte-class notation. The Forte class can be specified as string (e.g., 3-11) or as a list of cardinality and number (e.g., [8, 1]). If no match is available, None is returned. >>> chord.fromForteClass('3-11') >>> chord.fromForteClass('3-11b') >>> chord.fromForteClass('3-11a') >>> chord.fromForteClass((11, 1)) ''' card = None num = 1 inv = None if isinstance(notation, str): if '-' in notation: notationParts = notation.split('-') card = int(notationParts[0]) str_num, chars = common.getNumFromStr(notationParts[1]) num = int(str_num) if 'a' in chars.lower(): inv = 1 elif 'b' in chars.lower(): inv = -1 else: raise ChordException( f'cannot extract set-class representation from string: {notation}') elif common.isListLike(notation): if len(notation) <= 3: # assume it's a set-class representation if notation: card = notation[0] if len(notation) > 1: num = notation[1] if len(notation) > 2: inv = notation[2] else: raise ChordException(f'cannot handle specified notation: {notation}') else: raise ChordException(f'cannot handle specified notation: {notation}') prime = tables.addressToTransposedNormalForm([card, num, inv]) return Chord(prime) def fromIntervalVector(notation, getZRelation=False): ''' Return one or more Chords given an interval vector. >>> chord.fromIntervalVector([0, 0, 0, 0, 0, 1]) >>> chord.fromIntervalVector((5, 5, 5, 5, 5, 5)) is None True >>> chord.fromIntervalVector((1, 1, 1, 1, 1, 1)) >>> chord.fromIntervalVector((1, 1, 1, 1, 1, 1), getZRelation=True) >>> chord.fromIntervalVector((1, 1, 1, 1, 1, 1)).getZRelation() ''' addressList = None if common.isListLike(notation): if len(notation) == 6: # assume it's an interval vector addressList = tables.intervalVectorToAddress(notation) if addressList is None: raise ChordException(f'cannot handle specified notation: {notation}') post = [] for address in addressList: post.append(Chord(tables.addressToTransposedNormalForm(address))) # for now, return the first chord # z-related chords will have more than one if len(post) == 1: return post[0] elif len(post) == 2 and not getZRelation: return post[0] elif len(post) == 2 and getZRelation: return post[1] else: return None # ------------------------------------------------------------------------------ class Test(unittest.TestCase): ''' Most tests now in test/test_chord ''' def testCopyAndDeepcopy(self): from music21.test.commonTest import testCopyAll testCopyAll(self, globals()) _DOC_ORDER = [Chord] if __name__ == '__main__': import music21 music21.mainTest(Test) # , runTest='testInvertingSimple')