# -*- coding: utf-8 -*- # ------------------------------------------------------------------------------ # Name: reduceChords.py # Purpose: Tools for eliminating passing chords, etc. # # Authors: Michael Scott Asato Cuthbert # # Copyright: Copyright © 2013-14 Michael Scott Asato Cuthbert # License: BSD, see license.txt # ------------------------------------------------------------------------------ ''' Automatically reduce a MeasureStack to a single chord or group of chords. ''' from __future__ import annotations import copy import unittest from music21 import chord from music21.common.types import DocOrder from music21 import clef from music21 import meter from music21 import stream from music21 import tie def testMeasureStream1(): # noinspection PyShadowingNames ''' returns a simple measure stream for testing: >>> s = analysis.reduceChordsOld.testMeasureStream1() >>> s.show('text') {0.0} {0.0} {2.0} {3.0} ''' s = stream.Measure() t = meter.TimeSignature('4/4') c1 = chord.Chord('C4 E4 G4 C5') c1.quarterLength = 2.0 c2 = chord.Chord('C4 E4 F4 B4') c3 = chord.Chord('C4 E4 G4 C5') for c in [t, c1, c2, c3]: s.append(c) return s class ChordReducer: def __init__(self): self.printDebug = False self.weightAlgorithm = self.qlbsmpConsonance self.maxChords = 3 self.positionInMeasure = None self.numberOfElementsInMeasure = None # for working self._lastPitchedObject = None self._lastTs = None def reduceMeasureToNChords(self, measureObj, numChords=1, weightAlgorithm=None, trimBelow=0.25): ''' >>> s = analysis.reduceChordsOld.testMeasureStream1() >>> cr = analysis.reduceChordsOld.ChordReducer() Reduce to a maximum of 3 chords; though here we will only get one because the other chord is below the trimBelow threshold. >>> newS = cr.reduceMeasureToNChords(s, 3, ... weightAlgorithm=cr.qlbsmpConsonance, trimBelow = 0.3) >>> newS.show('text') {0.0} >>> newS.notes.first().quarterLength 4.0 ''' from music21 import note if measureObj.isFlat is False: mObj = measureObj.flatten().notes.stream() else: mObj = measureObj.notes.stream() chordWeights = self.computeMeasureChordWeights(mObj, weightAlgorithm) numChords = min(numChords, len(chordWeights)) maxNChords = sorted(chordWeights, key=chordWeights.get, reverse=True)[:numChords] if not maxNChords: r = note.Rest() r.quarterLength = mObj.duration.quarterLength for c in mObj: mObj.remove(c) mObj.insert(0, r) return mObj maxChordWeight = chordWeights[maxNChords[0]] trimmedMaxChords = [] for pcTuples in maxNChords: if chordWeights[pcTuples] >= maxChordWeight * trimBelow: trimmedMaxChords.append(pcTuples) # print(chordWeights[pcTuples], maxChordWeight) else: break currentGreedyChord = None currentGreedyChordPCs = None currentGreedyChordNewLength = 0.0 for c in mObj: if c.isNote: p = tuple(c.pitch.pitchClass) else: p = tuple({x.pitchClass for x in c.pitches}) if p in trimmedMaxChords and p != currentGreedyChordPCs: # keep this chord if currentGreedyChord is None and c.offset != 0.0: currentGreedyChordNewLength = c.offset c.offset = 0.0 elif currentGreedyChord is not None: currentGreedyChord.quarterLength = currentGreedyChordNewLength currentGreedyChordNewLength = 0.0 currentGreedyChord = c for n in c: n.tie = None if n.pitch.accidental is not None: n.pitch.accidental.displayStatus = None currentGreedyChordPCs = p currentGreedyChordNewLength += c.quarterLength else: currentGreedyChordNewLength += c.quarterLength mObj.remove(c) if currentGreedyChord is not None: currentGreedyChord.quarterLength = currentGreedyChordNewLength currentGreedyChordNewLength = 0.0 # even chord lengths for i in range(1, len(mObj)): c = mObj[i] cOffsetCurrent = c.offset cOffsetSyncop = cOffsetCurrent - int(cOffsetCurrent) if round(cOffsetSyncop, 3) in [0.250, 0.125, 0.333, 0.063, 0.062]: lastC = mObj[i - 1] lastC.quarterLength -= cOffsetSyncop c.offset = int(cOffsetCurrent) c.quarterLength += cOffsetSyncop # Remove zero-duration chords for c in list(mObj): if not c.quarterLength: mObj.remove(c) return mObj # closed position def computeMeasureChordWeights(self, measureObj, weightAlgorithm=None): ''' >>> s = analysis.reduceChordsOld.testMeasureStream1().notes >>> cr = analysis.reduceChordsOld.ChordReducer() >>> cws = cr.computeMeasureChordWeights(s) >>> for pcs in sorted(cws): ... print("%18r %2.1f" % (pcs, cws[pcs])) (0, 4, 7) 3.0 (0, 11, 4, 5) 1.0 Add beatStrength: >>> cws = cr.computeMeasureChordWeights(s, weightAlgorithm=cr.quarterLengthBeatStrength) >>> for pcs in sorted(cws): ... print("%18r %2.1f" % (pcs, cws[pcs])) (0, 4, 7) 2.2 (0, 11, 4, 5) 0.5 Give extra weight to the last element in a measure: >>> cws = cr.computeMeasureChordWeights(s, ... weightAlgorithm=cr.quarterLengthBeatStrengthMeasurePosition) >>> for pcs in sorted(cws): ... print("%18r %2.1f" % (pcs, cws[pcs])) (0, 4, 7) 3.0 (0, 11, 4, 5) 0.5 Make consonance count a lot: >>> cws = cr.computeMeasureChordWeights(s, weightAlgorithm=cr.qlbsmpConsonance) >>> for pcs in sorted(cws): ... print("%18r %2.1f" % (pcs, cws[pcs])) (0, 4, 7) 3.0 (0, 11, 4, 5) 0.5 ''' if weightAlgorithm is None: weightAlgorithm = self.quarterLengthOnly presentPCs = {} self.positionInMeasure = 0 self.numberOfElementsInMeasure = len(measureObj) for i, c in enumerate(measureObj): self.positionInMeasure = i if c.isNote: p = tuple(c.pitch.pitchClass) else: p = tuple({x.pitchClass for x in c.pitches}) if p not in presentPCs: presentPCs[p] = 0.0 presentPCs[p] += weightAlgorithm(c) self.positionInMeasure = 0 self.numberOfElementsInMeasure = 0 return presentPCs def quarterLengthOnly(self, c): return c.quarterLength def quarterLengthBeatStrength(self, c): return c.quarterLength * c.beatStrength def quarterLengthBeatStrengthMeasurePosition(self, c): if self.positionInMeasure == self.numberOfElementsInMeasure - 1: return c.quarterLength # call beatStrength 1 else: return self.quarterLengthBeatStrength(c) def qlbsmpConsonance(self, c): ''' Everything from before plus consonance ''' consonanceScore = 1.0 # if c.isConsonant() else 0.1 return self.quarterLengthBeatStrengthMeasurePosition(c) * consonanceScore def multiPartReduction(self, inStream, maxChords=2, closedPosition=False, forceOctave=False): ''' Return a multipart reduction of a stream. ''' i = 0 p = stream.Part() p0 = inStream.parts.first() if not p0: return p self._lastPitchedObject = None lenMeasures = len(p0.getElementsByClass(stream.Measure)) self._lastTs = None for i in range(lenMeasures): mI = inStream.measure(i, indicesNotNumbers=True) if not mI.recurse().notesAndRests: if i == 0: pass else: break else: m = self.reduceThisMeasure(mI, i, maxChords, closedPosition, forceOctave) p.coreAppend(m) if self.printDebug: print(i, ' ', end='') if i % 20 == 0 and i != 0: print('') p.coreElementsChanged() m = p.getElementsByClass(stream.Measure).first() if m: m.insert(0, clef.bestClef(p, allowTreble8vb=True)) p.makeNotation(inPlace=True) return p def reduceThisMeasure(self, mI, measureIndex, maxChords, closedPosition, forceOctave): m = stream.Measure() m.number = measureIndex mIChord = mI.chordify() newPart = self.reduceMeasureToNChords(mIChord, maxChords, weightAlgorithm=self.qlbsmpConsonance, trimBelow=0.3) # newPart.show('text') cLast = None cLastEnd = 0.0 for cEl in newPart: cElCopy = copy.deepcopy(cEl) if isinstance(cEl, chord.Chord) and closedPosition is not False: if forceOctave is not False: cElCopy.closedPosition(forceOctave=forceOctave, inPlace=True) else: cElCopy.closedPosition(inPlace=True) cElCopy.removeRedundantPitches(inPlace=True) newOffset = cEl.getOffsetBySite(newPart) # extend over gaps if cLast is not None: if round(newOffset - cLastEnd, 6) != 0.0: cLast.quarterLength += newOffset - cLastEnd cLast = cElCopy cLastEnd = newOffset + cElCopy.quarterLength m.coreInsert(newOffset, cElCopy, ignoreSort=True) tsContext = mI.parts.first().getContextByClass(meter.TimeSignature) if tsContext is not None: if round(tsContext.barDuration.quarterLength - cLastEnd, 6) != 0.0: cLast.quarterLength += tsContext.barDuration.quarterLength - cLastEnd m.coreElementsChanged() # add ties if self._lastPitchedObject is not None: firstPitched = m[0] if self._lastPitchedObject.isNote and firstPitched.isNote: if self._lastPitchedObject.pitch == firstPitched.pitch: self._lastPitchedObject.tie = tie.Tie('start') elif self._lastPitchedObject.isChord and firstPitched.isChord: if len(self._lastPitchedObject) == len(firstPitched): allSame = True for pitchI in range(len(self._lastPitchedObject)): if self._lastPitchedObject.pitches[pitchI] != firstPitched.pitches[pitchI]: allSame = False if allSame is True: self._lastPitchedObject.tie = tie.Tie('start') self._lastPitchedObject = m[-1] sourceMeasureTs = mI.parts.first().getElementsByClass(stream.Measure).first().timeSignature if sourceMeasureTs != self._lastTs: m.timeSignature = copy.deepcopy(sourceMeasureTs) self._lastTs = sourceMeasureTs return m # ------------------------------------------------------------------------------ class Test(unittest.TestCase): def testSimpleMeasure(self): s = stream.Measure() c1 = chord.Chord('C4 E4 G4 C5') c1.quarterLength = 2.0 c2 = chord.Chord('C4 E4 F4 B4') c3 = chord.Chord('C4 E4 G4 C5') for c in [c1, c2, c3]: s.append(c) class TestExternal(unittest.TestCase): show = True def testTrecentoMadrigal(self): from music21 import corpus # c = corpus.parse('beethoven/opus18no1', 2).measures(1, 19) c = corpus.parse('PMFC_06_Giovanni-05_Donna').measures(1, 30) # c = corpus.parse('PMFC_06_Giovanni-05_Donna').measures(90, 118) # c = corpus.parse('PMFC_06_Piero_1').measures(1, 10) # c = corpus.parse('PMFC_06-Jacopo').measures(1, 30) # c = corpus.parse('PMFC_12_13').measures(1, 40) # fix clef fixClef = True if fixClef: startClefs = c.parts[1].getElementsByClass(stream.Measure ).first().getElementsByClass(clef.Clef) if startClefs: clef1 = startClefs[0] c.parts[1].getElementsByClass(stream.Measure).first().remove(clef1) c.parts[1].getElementsByClass(stream.Measure).first().insert(0, clef.Treble8vbClef()) cr = ChordReducer() # cr.printDebug = True p = cr.multiPartReduction(c, maxChords=3) # p = cr.multiPartReduction(c, closedPosition=True) from music21 import key from music21 import roman cm = key.Key('G') for thisChord in p[chord.Chord]: thisChord.lyric = roman.romanNumeralFromChord(thisChord, cm, preferSecondaryDominants=True).figure c.insert(0, p) if self.show: c.show() # ------------------------------------------------------------------------------ # define presented order in documentation _DOC_ORDER: DocOrder = [] if __name__ == '__main__': import music21 music21.mainTest(Test)