music21.figuredBass.realizerScale

FiguredBassScale

class music21.figuredBass.realizerScale.FiguredBassScale(scaleValue='C', scaleMode='major')

Acts as a wrapper for Scale. Used to represent the concept of a figured bass scale, with a scale value and mode.

Accepted scale types: major, minor, dorian, phrygian, and hypophrygian. A FiguredBassScaleException is raised if an invalid scale type is provided.

>>> from music21.figuredBass import realizerScale
>>> fbScale = realizerScale.FiguredBassScale()
>>> fbScale.realizerScale
<music21.scale.MajorScale C major>
>>> fbScale.keySig
<music21.key.KeySignature of no sharps or flats>

>>> fbScale = realizerScale.FiguredBassScale('d', 'minor')
>>> fbScale.realizerScale
<music21.scale.MinorScale D minor>
>>> fbScale.keySig
<music21.key.KeySignature of 1 flat>

FiguredBassScale methods

FiguredBassScale.getPitchNames(bassPitch, notationString=None)

Takes a bassPitch and notationString and returns a list of corresponding pitch names based on the scale value and mode above and inclusive of the bassPitch name.

>>> from music21.figuredBass import realizerScale
>>> fbScale = realizerScale.FiguredBassScale()
>>> fbScale.getPitchNames('D3', '6')
['D', 'F', 'B']
>>> fbScale.getPitchNames('G3')
['G', 'B', 'D']
>>> fbScale.getPitchNames('B3', '6,#5')
['B', 'D', 'F#', 'G']
>>> fbScale.getPitchNames('C#3', '-7')  # Fully diminished seventh chord
['C#', 'E', 'G', 'B-']

FiguredBassScale.getPitches(bassPitch, notationString=None, maxPitch=None)

Takes in a bassPitch, a notationString, and a maxPitch representing the highest possible pitch that can be returned. Returns a sorted list of pitches which correspond to the pitches of each specific pitch name found through getPitchNames that fall between the bassPitch and the maxPitch, inclusive of both.

if maxPitch is None, then B5 s used instead.

>>> from music21.figuredBass import realizerScale
>>> fbScale = realizerScale.FiguredBassScale()

Root position triad

>>> [str(p) for p in fbScale.getPitches('C3') ]
['C3', 'E3', 'G3', 'C4', 'E4', 'G4', 'C5', 'E5', 'G5']

First inversion triad

>>> [str(p) for p in fbScale.getPitches('D3', '6') ]
['D3', 'F3', 'B3', 'D4', 'F4', 'B4', 'D5', 'F5', 'B5']

Root position seventh chord, showing MaxPitch

>>> fbScale.getPitches(pitch.Pitch('G3'), '7', 'F4')
[<music21.pitch.Pitch G3>, <music21.pitch.Pitch B3>,
 <music21.pitch.Pitch D4>, <music21.pitch.Pitch F4>]

FiguredBassScale.getSamplePitches(bassPitch, notationString=None)

Returns all pitches for a bassPitch and notationString within an octave of the bassPitch, inclusive of the bassPitch but exclusive at the upper bound. In other words, this method returns the most compact complete chord implied by the bassPitch and its figures.

>>> from music21.figuredBass import realizerScale
>>> fbScale = realizerScale.FiguredBassScale()

>>> fbScale.getSamplePitches('D3', '6')  # First inversion triad
[<music21.pitch.Pitch D3>, <music21.pitch.Pitch F3>, <music21.pitch.Pitch B3>]

Root position triad

>>> [str(p) for p in fbScale.getSamplePitches('G3') ]
['G3', 'B3', 'D4']

First inversion seventh chord

>>> [str(p) for p in fbScale.getSamplePitches('B3', '6,5') ]
['B3', 'D4', 'F4', 'G4']

Neapolitan chord

>>> [str(p) for p in fbScale.getSamplePitches('F3', '-6,-') ]
['F3', 'A-3', 'D-4']

Second inversion seventh chord

>>> [str(p) for p in fbScale.getSamplePitches('C5', '4,3') ]
['C5', 'E5', 'F5', 'A5']

Fully diminished seventh chord

>>> [str(p) for p in fbScale.getSamplePitches('C#3', '-7') ]
['C#3', 'E3', 'G3', 'B-3']

FiguredBassScale instance variables

FiguredBassScale.keySig

A KeySignature corresponding to the scale value and mode.

FiguredBassScale.realizerScale

A Scale based on the desired value and mode.