def _get_scale(self):
"""
Get music21 scale for a scale type
:param scale_type: major, minor, dorian etc.
"""
pitch, scale_type = self.key
if scale_type in [constants.MAJOR, constants.IONIAN]:
return scale.MajorScale(pitch)
elif scale_type in [constants.MINOR, constants.AEOLIAN]:
return scale.MinorScale(pitch)
elif scale_type == constants.DORIAN:
return scale.DorianScale(pitch)
elif scale_type == constants.PHRYGIAN:
return scale.PhrygianScale(pitch)
elif scale_type == constants.LYDIAN:
return scale.LydianScale(pitch)
elif scale_type == constants.LOCRIAN:
return scale.LocrianScale(pitch)
else:
return scale.MajorScale(pitch)
def testScales01(self):
from music21 import pitch
#==== "fig-py01"
# Providing a tonic makes this concrete
sc1 = scale.MajorScale('g4')
sc2 = scale.MajorScale('e-3')
# Comparing Concrete and Abstract Scales
assert (sc1 == sc2) == False
assert (sc1.abstract == sc2.abstract) == True
# Without arguments, getPitches() returns a single span
assert common.pitchList(
sc1.getPitches()) == '[G4, A4, B4, C5, D5, E5, F#5, G5]'
assert common.pitchList(sc2.getPitches(
'c2', 'c3')) == '[C2, D2, E-2, F2, G2, A-2, B-2, C3]'
# As a Chord, Scale pitches gain additional functionality
assert sc1.getChord().forteClass == '7-35'
# Given a degree, get the pitch
assert str(sc1.pitchFromDegree(5)) == 'D5'
assert common.pitchList(
sc2.pitchesFromScaleDegrees([7, 2], 'e-6',
'e-9')) == '[F6, D7, F7, D8, F8, D9]'
# Get a scale degree from a pitch
assert sc1.getScaleDegreeFromPitch('d') == 5
assert sc2.getScaleDegreeFromPitch('d') == 7
# Get the next pitch given step directions
match = [pitch.Pitch('g2')]
for direction in [1, 1, 1, -2, 4, -1, 1, 1, 1]:
# Append the next pitch based on the last-added pitch
match.append(sc1.next(match[-1], direction))
assert common.pitchList(
match), '[G2, A2, B2, C3, A2, E3, D3, E3, F#3, G3]'
# Derive new scales based on a provided collection or degree
assert str(sc1.derive(['c4', 'g4', 'b8',
'f2'])) == '<music21.scale.MajorScale C major>'
assert str(sc1.deriveByDegree(
7, 'C#')) == '<music21.scale.MajorScale D major>'
# Methods unique to DiatonicScale subclasses
assert str(
sc2.getRelativeMinor()) == '<music21.scale.MinorScale C minor>'
#==== "fig-py01" end
#==== "fig-py02"
sc1 = scale.PhrygianScale('g4')
assert common.pitchList(
sc1.getPitches()) == '[G4, A-4, B-4, C5, D5, E-5, F5, G5]'
assert str(
sc1.getRelativeMajor()) == '<music21.scale.MajorScale E- major>'
assert str(sc1.getTonic()), str(sc1.getDominant()) == ('G4', 'D5')
sc2 = scale.HypodorianScale('a6')
assert common.pitchList(sc2.getPitches(
'e2', 'e3')) == '[E2, F#2, G2, A2, B2, C3, D3, E3]'
assert str(
sc2.getRelativeMajor()) == '<music21.scale.MajorScale G major>'
assert str(sc2.getTonic()), str(sc2.getDominant()) == ('A6', 'C7')
#==== "fig-py02" end
#==== "fig-py06"
# see below
#==== "fig-py06" end
#==== "fig-py03"
#print('\n\nfig-py03')
sc1 = scale.HarmonicMinorScale('a3')
assert common.pitchList(
sc1.getPitches()) == '[A3, B3, C4, D4, E4, F4, G#4, A4]'
assert str(sc1.getTonic()), str(sc1.getDominant()) == ('A3', 'E4')
s = stream.Stream()
for d in [1, 3, 2, 1, 6, 5, 8, 7, 8]:
s.append(
note.Note(sc1.pitchFromDegree(d, equateTermini=False),
type='eighth'))
#s.show()
#==== "fig-py03" end
#==== "fig-py04"
import random
sc1 = scale.MelodicMinorScale('c4')
assert common.pitchList(sc1.getPitches(
direction='ascending')) == '[C4, D4, E-4, F4, G4, A4, B4, C5]'
assert common.pitchList(
sc1.getPitches('c3', 'c5', direction='descending')) == (
'[C5, B-4, A-4, G4, F4, E-4, D4, ' +
'C4, B-3, A-3, G3, F3, E-3, D3, C3]')
assert str(sc1.getTonic()), str(sc1.getDominant()) == ('C4', 'G4')
s = stream.Stream()
p = None
for i in range(8): # was 16, but sometimes exceeded scale length.
direction = random.choice([-1, 1])
for j in range(2):
p = sc1.next(p, direction)
s.append(note.Note(p, quarterLength=.25))
#s.show()
#==== "fig-py04" end
#==== "fig-py05"
sc1 = scale.OctatonicScale('e3', 'm2')
assert common.pitchList(
sc1.getPitches()) == '[E3, F3, G3, A-3, B-3, C-4, D-4, D4, E4]'
sc2 = scale.OctatonicScale('e3', 'M2')
assert common.pitchList(
sc2.getPitches()) == '[E3, F#3, G3, A3, B-3, C4, D-4, E-4, F-4]'
part1 = stream.Part()
part2 = stream.Part()
durPart1 = [1, 1, 0.5, 0.5, 1]
durPart2 = [3, 1]
degrees = list(range(1, 9))
for unused in range(4):
random.shuffle(degrees)
random.shuffle(durPart1)
random.shuffle(durPart2)
i = 0
for dur in durPart1:
part1.append(
note.Note(sc2.pitchFromDegree(degrees[i]),
quarterLength=dur))
i += 1
for dur in durPart2:
part2.append(
note.Note(sc2.pitchFromDegree(degrees[i],
minPitch='c2',
maxPitch='c3'),
quarterLength=dur))
i += 1
s = stream.Score()
s.insert(0, part1)
s.insert(0, part2)
#s.show()
# add notation example; perhaps create tri-chords from scale-completing selections
#==== "fig-py05" end
#sc = scale.SieveScale('c2', '(-3@2 & 4) | (-3@1 & 4@1) | (3@2 & 4@2) | (-3 & 4@3)')
#==== "fig-py07"
# add examples
sc1 = scale.SieveScale('c4', '3@0|4@0')
self.assertEqual(common.pitchList(sc1.getPitches()),
'[C4, E-4, E4, F#4, G#4, A4, C5]')
sc2 = scale.SieveScale('c4', '5@0|7@0')
self.assertEqual(
common.pitchList(sc2.getPitches()),
'[C4, F4, G4, B-4, D5, E-5, G#5, A5, C#6, E6, F#6, B6]')
s = stream.Stream()
pColection = sc2.getPitches('c3', 'c7')
random.shuffle(pColection)
for p in pColection:
s.append(note.Note(p, type='16th'))
#s.show()
#==== "fig-py07" end
#==== "fig-py08"
sc1 = scale.RagAsawari('g3')
self.assertEqual(
common.pitchList(sc1.getPitches(direction='ascending')),
'[G3, A3, C4, D4, E-4, G4]')
self.assertEqual(
common.pitchList(sc1.getPitches(direction='descending')),
'[G4, F4, E-4, D4, C4, B-3, A3, G3]')
sc2 = scale.RagMarwa('g3')
assert common.pitchList(sc2.getPitches(direction='ascending')
) == '[G3, A-3, B3, C#4, E4, F#4, E4, G4, A-4]'
assert common.pitchList(
sc2.getPitches(direction='descending'
)) == '[A-4, G4, A-4, F#4, E4, C#4, B3, A-3, G3]'
p1 = None
s = stream.Stream()
for direction in ([1] * 10) + ([-1] * 8) + ([1] * 4) + ([-1] *
3) + ([1] * 4):
p1 = sc1.next(p1, direction)
s.append(note.Note(p1, quarterLength=.25))
#s.show()
p1 = None
s = stream.Stream()
for direction in ([1] * 10) + ([-1] * 8) + ([1] * 4) + ([-1] *
3) + ([1] * 4):
p1 = sc2.next(p1, direction)
s.append(note.Note(p1, quarterLength=.25))
#s.show()
#==== "fig-py08" end
#==== "fig-py09"
#import random
sc1 = scale.WeightedHexatonicBlues('c3')
p = 'c3'
s = stream.Stream()
for n in range(32):
p = sc1.next(p, random.choice([-1, 1]))
n = note.Note(p, quarterLength=random.choice([.5, .25, .25]))
s.append(n)
