music21.pitch

Classes for representing and manipulating pitches, pitch-space, and accidentals.

Each Note object has a Pitch object embedded in it. Some methods below, such as Pitch.name, Pitch.step, etc. are made available directly in the Note object, so they will seem familiar.

Pitch

class music21.pitch.Pitch(name: str | int | float | None = None, *, step: Literal['C', 'D', 'E', 'F', 'G', 'A', 'B'] | None = None, octave: int | None = None, accidental: Accidental | str | int | float | None = None, microtone: Microtone | int | float | None = None, pitchClass: int | Literal['a', 'A', 't', 'T', 'b', 'B', 'e', 'E'] | None = None, midi: int | None = None, ps: float | None = None, fundamental: Pitch | None = None, **keywords)

A fundamental object that represents a single pitch.

Pitch objects are most often created by passing in a note name (C, D, E, F, G, A, B), an optional accidental (one or more “#”s or “-“s, where “-” means flat), and an optional octave number:

>>> highEflat = pitch.Pitch('E-6')
>>> highEflat.name
'E-'
>>> highEflat.step
'E'
>>> highEflat.accidental
<music21.pitch.Accidental flat>
>>> highEflat.octave
6

The .nameWithOctave property gives back what we put in, ‘E-6’:

>>> highEflat.nameWithOctave
'E-6'

Pitch objects represent themselves as the class name followed by the .nameWithOctave:

>>> p1 = pitch.Pitch('a#4')
>>> p1
<music21.pitch.Pitch A#4>

Printing a pitch.Pitch object or converting it to a string gives a more compact form:

>>> print(p1)
A#4
>>> str(p1)
'A#4'

Warning

A Pitch without an accidental has a .accidental of None, not Natural. This can lead to problems if you assume that every Pitch or Note has a .accidental that you can call .alter or something like that on:

>>> c = pitch.Pitch('C4')
>>> c.accidental is None
True

>>> alters = []
>>> for pName in ['G#5', 'B-5', 'C6']:
...     p = pitch.Pitch(pName)
...     alters.append(p.accidental.alter)
Traceback (most recent call last):
AttributeError: 'NoneType' object has no attribute 'alter'
>>> alters
[1.0, -1.0]

If a Pitch doesn’t have an associated octave, then its .octave value is None. This means that it represents any G#, regardless of octave. Transposing this note up an octave doesn’t change anything.

>>> anyGSharp = pitch.Pitch('G#')
>>> anyGSharp.octave is None
True
>>> print(anyGSharp.transpose('P8'))
G#

Sometimes we need an octave for a Pitch even if it’s not specified. For instance, we can’t play an octave-less Pitch in MIDI or display it on a staff. So there is an .implicitOctave tag to deal with these situations; by default it’s always 4 (unless defaults.pitchOctave is changed)

>>> anyGSharp.implicitOctave
4

If a Pitch has its .octave explicitly set, then .implicitOctave always equals .octave.

>>> highEflat.implicitOctave
6

If an integer or float >= 12 is passed to the constructor then it is used as the .ps attribute, which is for most common piano notes, the same as a MIDI number:

>>> pitch.Pitch(65)
<music21.pitch.Pitch F4>

>>> pitch.Pitch(65.5).accidental
<music21.pitch.Accidental half-sharp>

A pitch.Pitch object can also be created using only a number from 0-11, that number is taken to be a pitchClass, where 0 = C, 1 = C#/D-, etc. and no octave is set.

>>> p2 = pitch.Pitch(3)
>>> p2
<music21.pitch.Pitch E->
>>> p2.octave is None
True

Since in instantiating pitches from numbers, pitch.Pitch(3) could be either a D# or an E-flat, this Pitch object has an attribute called .spellingIsInferred that is set to True. That means that when it is transposed or displayed, other functions or programs should feel free to substitute an enharmonically equivalent pitch in its place:

>>> p2.spellingIsInferred
True
>>> p1.spellingIsInferred
False

As MIDI numbers < 12 are almost unheard of in actual music, there is unlikely to be confusion between a pitchClass instantiation and a MIDI number instantiation, but if one must be clear, use midi= in the constructor:

>>> lowE = pitch.Pitch(midi=3)
>>> lowE.name, lowE.octave
('E-', -1)

Instead of using a single string or integer for creating the object, a succession of named keywords can be used instead:

>>> p3 = pitch.Pitch(name='C', accidental='#', octave=7, microtone=-30)
>>> p3.fullName
'C-sharp in octave 7 (-30c)'

The full list of supported keywords are: name, accidental (which can be a string or an Accidental object), octave, microtone (which can be a number or a Microtone object), pitchClass (0-11), fundamental (another Pitch object representing the fundamental for this harmonic; harmonic is not yet supported, but should be), and midi or ps (two ways of specifying nearly the same thing, see below).

Using keywords to create Pitch objects is especially important if extreme pitches might be found. For instance, the first Pitch is B-double flat in octave 3, not B-flat in octave -3. The second object creates that low Pitch properly:

>>> p4 = pitch.Pitch('B--3')
>>> p4.accidental
<music21.pitch.Accidental double-flat>
>>> p4.octave
3

>>> p5 = pitch.Pitch(step='B', accidental='-', octave=-3)
>>> p5.accidental
<music21.pitch.Accidental flat>
>>> p5.octave
-3

Internally, pitches are represented by their scale step (self.step), their octave, and their accidental. Pitch objects use these three elements to figure out their pitch space representation (self.ps); altering any of the first three changes the pitch space (ps) representation. Similarly, altering the .ps representation alters the first three.

>>> aSharp = pitch.Pitch('A#5')
>>> aSharp.ps
82.0

>>> aSharp.octave = 4
>>> aSharp.ps
70.0

>>> aSharp.ps = 60.0
>>> aSharp.nameWithOctave
'C4'

Two Pitches are equal if they represent the same pitch and are spelled the same (enharmonics do not count). A Pitch is greater than another Pitch if its .ps is greater than the other. Thus, C##4 > D-4.

>>> pitch.Pitch('C#5') == pitch.Pitch('C#5')
True
>>> pitch.Pitch('C#5') == pitch.Pitch('D-5')
False
>>> pitch.Pitch('C##5') > pitch.Pitch('D-5')
True

A consequence of comparing enharmonics for equality but .ps for comparisons is that a Pitch can be neither less than nor greater than another Pitch without being equal:

>>> pitch.Pitch('C#5') == pitch.Pitch('D-5')
False
>>> pitch.Pitch('C#5') > pitch.Pitch('D-5')
False
>>> pitch.Pitch('C#5') < pitch.Pitch('D-5')
False

To check for enharmonic equality, use the .ps attribute:

>>> pitch.Pitch('C#5').ps == pitch.Pitch('D-5').ps
True

Advanced construction of pitch with keywords:

>>> pitch.Pitch(name='D', accidental=pitch.Accidental('double-flat'))
<music21.pitch.Pitch D-->
>>> f = pitch.Pitch(pitchClass=5, octave=4,
...                 microtone=pitch.Microtone(30), fundamental=pitch.Pitch('B-2'))
>>> f
<music21.pitch.Pitch F4(+30c)>
>>> f.fundamental
<music21.pitch.Pitch B-2>

If contradictory keyword attributes (like name=’E-’, accidental=’#’) are passed in, behavior is not defined, but unlikely to make you happy.

Pitches are ProtoM21Objects, so they retain some attributes there such as .classes and .groups, but they don’t have Duration or Sites objects and cannot be put into Streams

Pitch bases

• ProtoM21Object

Pitch read-only properties

Pitch.alter

Get the number of half-steps shifted by this pitch, such as 1.0 for a sharp, -1.0 for a flat, 0.0 for a natural, 2.0 for a double sharp, and -0.5 for a quarter tone flat.

Thus, the alter value combines the pitch change suggested by the Accidental and the Microtone combined.

>>> p = pitch.Pitch('g#4')
>>> p.alter
1.0
>>> p.microtone = -25  # in cents
>>> p.alter
0.75

To change the alter value, change either the accidental or the microtone.

Pitch.french

Read-only attribute. Returns the name of a Pitch in the French system (where A = la, B = si, B-flat = si bémol, C-sharp = do dièse, etc.) (Microtones and Quarter tones raise an error). Note that do is used instead of the also acceptable ut.

>>> print(pitch.Pitch('B-').french)
si bémol

>>> print(pitch.Pitch('B').french)
si

>>> print(pitch.Pitch('E-').french)
mi bémol

>>> print(pitch.Pitch('C#').french)
do dièse

>>> print(pitch.Pitch('A--').french)
la double bémol

>>> p1 = pitch.Pitch('C')
>>> p1.accidental = pitch.Accidental('half-sharp')
>>> p1.french
Traceback (most recent call last):
music21.pitch.PitchException: On ne peut pas utiliser les microtones avec "french."
    Quelle Dommage!

Pitch.fullName

Return the most complete representation of this Pitch, providing name, octave, accidental, and any microtonal adjustments.

>>> p = pitch.Pitch('A-3')
>>> p.microtone = 33.33
>>> p.fullName
'A-flat in octave 3 (+33c)'

>>> p = pitch.Pitch('A`7')
>>> p.fullName
'A-half-flat in octave 7'

Pitch.german

Read-only property. Returns a unicode string of the name of a Pitch in the German system (where B-flat = B, B = H, etc.) (Microtones and Quarter tones raise an error). Note that Ases is used instead of the also acceptable Asas.

>>> print(pitch.Pitch('B-').german)
B
>>> print(pitch.Pitch('B').german)
H
>>> print(pitch.Pitch('E-').german)
Es
>>> print(pitch.Pitch('C#').german)
Cis
>>> print(pitch.Pitch('A--').german)
Ases
>>> p1 = pitch.Pitch('C')
>>> p1.accidental = pitch.Accidental('half-sharp')
>>> p1.german
Traceback (most recent call last):
music21.pitch.PitchException:
    Es geht nicht "german" zu benutzen mit Microtönen.  Schade!

Note these rarely used pitches:

>>> print(pitch.Pitch('B--').german)
Heses
>>> print(pitch.Pitch('B#').german)
His

Pitch.implicitOctave

Returns the octave of the Pitch, or defaultOctave if octave was never set. To set an octave, use .octave. Default octave is usually 4.

>>> p = pitch.Pitch('C#')
>>> p.octave is None
True
>>> p.implicitOctave
4

Cannot be set. Instead, just change the .octave of the pitch

Pitch.italian

Read-only attribute. Returns the name of a Pitch in the Italian system (F-sharp is fa diesis, C-flat is do bemolle, etc.) (Microtones and Quarter tones raise an error).

>>> print(pitch.Pitch('B-').italian)
si bemolle
>>> print(pitch.Pitch('B').italian)
si
>>> print(pitch.Pitch('E-9').italian)
mi bemolle
>>> print(pitch.Pitch('C#').italian)
do diesis
>>> print(pitch.Pitch('A--4').italian)
la doppio bemolle
>>> p1 = pitch.Pitch('C')
>>> p1.accidental = pitch.Accidental('half-sharp')
>>> p1.italian
Traceback (most recent call last):
music21.pitch.PitchException: Non si puo usare `italian` con microtoni

Note these rarely used pitches:

>>> print(pitch.Pitch('E####').italian)
mi quadruplo diesis
>>> print(pitch.Pitch('D---').italian)
re triplo bemolle

Pitch.spanish

Read-only attribute. Returns the name of a Pitch in Spanish (Microtones and Quarter tones raise an error).

>>> print(pitch.Pitch('B-').spanish)
si bemol
>>> print(pitch.Pitch('E-').spanish)
mi bemol
>>> print(pitch.Pitch('C#').spanish)
do sostenido
>>> print(pitch.Pitch('A--').spanish)
la doble bemol
>>> p1 = pitch.Pitch('C')
>>> p1.accidental = pitch.Accidental('half-sharp')
>>> p1.spanish
Traceback (most recent call last):
music21.pitch.PitchException: Unsupported accidental type.

Note these rarely used pitches:

>>> print(pitch.Pitch('B--').spanish)
si doble bemol
>>> print(pitch.Pitch('B#').spanish)
si sostenido

Pitch.unicodeName

Name presently returns pitch name and accidental without octave.

>>> a = pitch.Pitch('G#')
>>> a.unicodeName
'G♯'

Pitch.unicodeNameWithOctave

Return the pitch name with octave with unicode accidental symbols, if available.

Read-only property.

>>> p = pitch.Pitch('C#4')
>>> p.unicodeNameWithOctave
'C♯4'

Read-only properties inherited from ProtoM21Object:

classSet

classes

Pitch read/write properties

Pitch.accidental

Stores an optional accidental object contained within the Pitch object. This might return None, which is different from a natural accidental:

>>> a = pitch.Pitch('E-')
>>> a.accidental.alter
-1.0
>>> a.accidental.modifier
'-'

>>> b = pitch.Pitch('C4')
>>> b.accidental is None
True
>>> b.accidental = pitch.Accidental('natural')
>>> b.accidental is None
False
>>> b.accidental
<music21.pitch.Accidental natural>

Pitch.diatonicNoteNum

Returns (or takes) an integer that uniquely identifies the diatonic version of a note, that is ignoring accidentals. The number returned is the diatonic interval above C0 (the lowest C on a Bösendorfer Imperial Grand), so G0 = 5, C1 = 8, etc. Numbers can be negative for very low notes.

C4 (middleC) = 29, C#4 = 29, C##4 = 29, D-4 = 30, D4 = 30, etc.

>>> c = pitch.Pitch('c4')
>>> c.diatonicNoteNum
29

Unlike MIDI numbers (or .ps), C and C# has the same diatonicNoteNum:

>>> c = pitch.Pitch('c#4')
>>> c.diatonicNoteNum
29

But D-double-flat has a different diatonicNoteNum than C.

>>> d = pitch.Pitch('d--4')
>>> d.accidental.name
'double-flat'
>>> d.diatonicNoteNum
30

>>> lowC = pitch.Pitch('c1')
>>> lowC.diatonicNoteNum
8

>>> b = pitch.Pitch()
>>> b.step = 'B'
>>> b.octave = -1
>>> b.diatonicNoteNum
0

An implicitOctave of 4 is used if octave is not set:

>>> c = pitch.Pitch('C')
>>> c.diatonicNoteNum
29

diatonicNoteNum can also be set. Changing it does not change the Accidental associated with the Pitch.

>>> lowDSharp = pitch.Pitch('C#7')  # start high !!!
>>> lowDSharp.diatonicNoteNum = 9  # move low
>>> lowDSharp.octave
1
>>> lowDSharp.name
'D#'

Negative diatonicNoteNums are possible, in case, like John Luther Adams, you want to notate the sounds of sub-sonic Earth rumblings.

>>> lowLowA = pitch.Pitch('A')
>>> lowLowA.octave = -1
>>> lowLowA.diatonicNoteNum
-1

>>> lowLowLowD = pitch.Pitch('D')
>>> lowLowLowD.octave = -3
>>> lowLowLowD.diatonicNoteNum
-19

Pitch.freq440

Gets the frequency of the note as if it’s in an equal temperament context where A4 = 440hz. The same as .frequency so long as no other temperaments are currently being used.

Since we don’t have any other temperament objects at present, this is the same as .frequency always.

>>> a = pitch.Pitch('A4')
>>> a.freq440
440.0

Pitch.frequency

The frequency property gets or sets the frequency of the pitch in hertz.

If the frequency has not been overridden, then it is computed based on A440Hz and equal temperament

>>> a = pitch.Pitch()
>>> a.frequency = 440.0
>>> a.frequency
440.0
>>> a.name
'A'
>>> a.octave
4

Microtones are captured if the frequency doesn’t correspond to any standard note.

>>> a.frequency = 450.0
>>> a
<music21.pitch.Pitch A~4(-11c)>

Pitch.groups

Similar to Groups on music21 object, returns or sets a Groups object.

Pitch.microtone

Returns or sets the microtone object contained within the Pitch object. Microtones must be supplied in cents.

>>> p = pitch.Pitch('E-4')
>>> p.microtone.cents == 0
True
>>> p.ps
63.0
>>> p.microtone = 33  # adjustment in cents
>>> str(p)
'E-4(+33c)'
>>> p.microtone
<music21.pitch.Microtone (+33c)>

>>> (p.name, p.nameWithOctave)  # these representations are unchanged
('E-', 'E-4')
>>> p.microtone = '(-12c'  # adjustment in cents
>>> p
<music21.pitch.Pitch E-4(-12c)>
>>> p.microtone = pitch.Microtone(-30)
>>> p
<music21.pitch.Pitch E-4(-30c)>

Pitch.midi

Get or set a pitch value in MIDI. MIDI pitch values are like ps values (pitchSpace) rounded to the nearest integer; while the ps attribute will accommodate floats.

>>> c = pitch.Pitch('C4')
>>> c.midi
60
>>> c.midi =  23.5
>>> c.midi
24

Note that like ps (pitchSpace), MIDI notes do not distinguish between sharps and flats, etc.

>>> dSharp = pitch.Pitch('D#4')
>>> dSharp.midi
63
>>> eFlat = pitch.Pitch('E-4')
>>> eFlat.midi
63

Midi values are constrained to the space 0-127. Higher or lower values will be transposed octaves to fit in this space.

>>> veryHighFHalfFlat = pitch.Pitch('F')
>>> veryHighFHalfFlat.octave = 12
>>> veryHighFHalfFlat.accidental = pitch.Accidental('half-flat')
>>> veryHighFHalfFlat
<music21.pitch.Pitch F`12>
>>> veryHighFHalfFlat.ps
160.5
>>> veryHighFHalfFlat.midi
125
>>> veryHighFHalfFlat.octave = 9
>>> veryHighFHalfFlat.midi
125

>>> notAsHighNote = pitch.Pitch()
>>> notAsHighNote.ps = veryHighFHalfFlat.midi
>>> notAsHighNote
<music21.pitch.Pitch F9>

Note that the conversion of improper midi values to proper midi values is done before assigning .ps:

>>> a = pitch.Pitch()
>>> a.midi = -10
>>> a.midi
2
>>> a.ps
2.0
>>> a.spellingIsInferred
True

More absurd octaves:

>>> p = pitch.Pitch('c~4')
>>> p.octave = -1
>>> p.ps
0.5
>>> p.midi
1
>>> p.octave = -2
>>> p.ps
-11.5
>>> p.midi
1

Pitch.name

Gets or sets the name (pitch name with accidental but without octave) of the Pitch.

>>> p = pitch.Pitch('D#5')
>>> p.name
'D#'

>>> p.name = 'C#'
>>> p.name
'C#'

>>> a = pitch.Pitch('G#')
>>> a.name
'G#'

Does not simplify enharmonics

>>> a = pitch.Pitch('B---')
>>> a.name
'B---'

Pitch.nameWithOctave

Return or set the pitch name with an octave designation. If no octave as been set, no octave value is returned.

>>> gSharp = pitch.Pitch('G#4')
>>> gSharp.nameWithOctave
'G#4'

>>> dFlatFive = pitch.Pitch()
>>> dFlatFive.step = 'D'
>>> dFlatFive.accidental = pitch.Accidental('flat')
>>> dFlatFive.octave = 5
>>> dFlatFive.nameWithOctave
'D-5'
>>> dFlatFive.nameWithOctave = 'C#6'
>>> dFlatFive.name
'C#'
>>> dFlatFive.octave
6

N.B. – it’s generally better to set the name and octave separately, especially since you may at some point encounter very low pitches such as “A octave -1”, which will be interpreted as “A-flat, octave 1”. Our crude setting algorithm also does not support octaves above 9.

>>> lowA = pitch.Pitch()
>>> lowA.name = 'A'
>>> lowA.octave = -1
>>> lowA.nameWithOctave
'A-1'
>>> lowA.nameWithOctave = lowA.nameWithOctave
>>> lowA.name
'A-'
>>> lowA.octave
1

Octave must be included in nameWithOctave or an exception is raised:

>>> a = pitch.Pitch()
>>> a.nameWithOctave = 'C#9'
>>> a.nameWithOctave = 'C#'
Traceback (most recent call last):
music21.pitch.PitchException: Cannot set a nameWithOctave with 'C#'

Set octave to None explicitly instead.

Pitch.octave

Returns or sets the octave of the note. Setting the octave updates the pitchSpace attribute.

>>> a = pitch.Pitch('g')
>>> a.octave is None
True
>>> a.implicitOctave
4
>>> a.ps  ## will use implicitOctave
67.0
>>> a.name
'G'

>>> a.octave = 14
>>> a.octave
14
>>> a.implicitOctave
14
>>> a.name
'G'
>>> a.ps
187.0

Pitch.pitchClass

Returns or sets the integer value for the pitch, 0-11, where C=0, C#=1, D=2, etc. to B=11. Can be set using integers (0-11) or ‘A’ or ‘B’ for 10 or 11.

>>> a = pitch.Pitch('a3')
>>> a.pitchClass
9
>>> dis = pitch.Pitch('d3')
>>> dis.pitchClass
2
>>> dis.accidental = pitch.Accidental('#')
>>> dis.pitchClass
3

If a string “A” or “B” is given to pitchClass, it is still returned as an int.

>>> dis.pitchClass = 'A'
>>> dis.pitchClass
10
>>> dis.name
'B-'

Extreme octaves will not affect pitchClass

>>> dis.octave = -10
>>> dis.pitchClass
10

In the past, certain microtones and/or octaves were returning pc 12! This is now fixed.

>>> flattedC = pitch.Pitch('C4')
>>> flattedC.microtone = -4
>>> print(flattedC)
C4(-4c)
>>> flattedC.pitchClass
0
>>> print(flattedC.ps)
59.96
>>> flattedC.octave = -3
>>> print(flattedC.ps)
-24.04
>>> flattedC.pitchClass
0

Note that the pitchClass of a microtonally altered pitch is the pitch class of the nearest pitch. Python 3 uses the “round-to-even” method so C~4 (C half sharp 4) is pitchClass 0, since 60.5 rounds to 60.0

>>> p = pitch.Pitch('C~4')
>>> p.ps
60.5
>>> p.pitchClass
0

However, for backwards compatability, the MIDI number of a microtone is created by using “schoolyard” rounding which always rounds 0.5 upwards, which can cause some unusual behavior:

>>> p.midi
61
>>> pitch.Pitch(midi=p.midi).pitchClass
1

This means that pitchClass + microtone is NOT a good way to estimate the frequency of a pitch. For instance, if we take a pitch that is 90% of the way between pitchClass 0 (C) and pitchClass 1 (C#/D-flat), this formula gives an inaccurate answer of 1.9, not 0.9:

>>> p = pitch.Pitch('C4')
>>> p.microtone = 90
>>> p
<music21.pitch.Pitch C4(+90c)>
>>> p.pitchClass + (p.microtone.cents / 100.0)
1.9

More examples of setting the pitchClass.

>>> a = pitch.Pitch('a3')
>>> a.pitchClass = 3
>>> a
<music21.pitch.Pitch E-3>
>>> a.spellingIsInferred
True
>>> a.pitchClass = 'A'
>>> a
<music21.pitch.Pitch B-3>

Changing pitchClass does not remove microtones.

>>> a.microtone = 20
>>> a.pitchClass = 1
>>> a
<music21.pitch.Pitch C#3(+20c)>

Pitch.pitchClassString

Returns or sets a string representation of the pitch class, where integers greater than 10 are replaced by A and B, respectively. Can be used to set pitch class by a string representation as well (though this is also possible with pitchClass).

>>> a = pitch.Pitch('a#3')
>>> a.pitchClass
10
>>> a.pitchClassString
'A'

We can set the pitchClassString as well:

>>> a.pitchClassString = 'B'
>>> a.pitchClass
11

Pitch.ps

The ps property permits getting and setting a pitch space value, a floating point number representing pitch space, where 60.0 is C4, middle C, 61.0 is C#4 or D-4, and floating point values are microtonal tunings (0.01 is equal to one cent), so a quarter-tone sharp above C5 is 72.5.

Note that the choice of 60.0 for C4 makes it identical to the integer value of 60 for .midi, but .midi does not allow for microtones and is limited to 0-127 while .ps allows for notes before midi 0 or above midi 127.

>>> a = pitch.Pitch('C4')
>>> a.ps
60.0

Changing the ps value for a will change the step and octave:

>>> a.ps = 45
>>> a
<music21.pitch.Pitch A2>
>>> a.ps
45.0

Notice that ps 61 represents both C# and D-flat. Thus, “spellingIsInferred” will be true after setting our pitch to 61:

>>> a.ps = 61
>>> a
<music21.pitch.Pitch C#4>
>>> a.ps
61.0
>>> a.spellingIsInferred
True

Microtonal accidentals and pure Microtones are allowed, as are extreme ranges:

>>> b = pitch.Pitch('B9')
>>> b.accidental = pitch.Accidental('half-flat')
>>> b
<music21.pitch.Pitch B`9>
>>> b.ps
130.5

>>> p = pitch.Pitch('c4')
>>> p.microtone = 20
>>> print('%.1f' % p.ps)
60.2

Octaveless pitches use their .implicitOctave attributes:

>>> d = pitch.Pitch('D#')
>>> d.octave is None
True
>>> d.implicitOctave
4
>>> d.ps
63.0

>>> d.octave = 5
>>> d.ps
75.0

Setting with microtones

>>> p = pitch.Pitch()
>>> p.ps = 61
>>> p.ps
61.0
>>> p.spellingIsInferred
True
>>> p.ps = 61.5  # get a quarter tone
>>> p
<music21.pitch.Pitch C#~4>
>>> p.ps = 61.7  # set a microtone
>>> print(p)
C#~4(+20c)
>>> p.ps = 61.4  # set a microtone
>>> print(p)
C#~4(-10c)

The property is called when self.step, self.octave or self.accidental are changed.

Pitch.step

The diatonic name of the note; i.e. does not give the accidental or octave.

>>> a = pitch.Pitch('B-3')
>>> a.step
'B'

Upper-case or lower-case names can be given to .step – they will be converted to upper-case

>>> b = pitch.Pitch()
>>> b.step = 'c'
>>> b.step
'C'

Changing the .step does not change the .accidental or .octave:

>>> a = pitch.Pitch('F#5')
>>> a.step = 'D'
>>> a.nameWithOctave
'D#5'

Giving a value that includes an accidental raises a PitchException. Use .name instead to change that.

>>> b = pitch.Pitch('E4')
>>> b.step = 'B-'
Traceback (most recent call last):
music21.pitch.PitchException: Cannot make a step out of 'B-'

This is okay though:

>>> b.name = 'B-'

Note that if spelling is inferred, setting the step does NOT give that enharmonic. Perhaps it should, but best to make people use .getLowerEnharmonic or .getHigherEnharmonic instead.

>>> b.ps = 60
>>> b.nameWithOctave
'C4'
>>> b.spellingIsInferred
True
>>> b.step = 'B'
>>> b.accidental is None  # maybe this should set to B#? But that could be screwy.
True
>>> b.spellingIsInferred
False

Pitch methods

Pitch.__eq__(other: object)

Are two pitches equal?

They must both sound the same and be spelled the same. Enharmonic equivalence is not equality, nor is impliedOctave or is a pitch without an accidental equal to a pitch with a natural accidental. (See :meth:`~music21.pitch.Pitch.isEnharmonic for a method that does not require spelling equivalence, and for an example of how to compare notes without accidentals to notes with natural accidentals.)

>>> c = pitch.Pitch('C2')
>>> c.octave
2
>>> cs = pitch.Pitch('C#4')
>>> cs.octave
4
>>> c == cs
False
>>> c != cs
True

>>> seven = 7
>>> c == seven
False

>>> c != seven
True

>>> df = pitch.Pitch('D-4')
>>> cs == df
False

Implied octaves do not equal explicit octaves

>>> c4 = pitch.Pitch('C4')
>>> cImplied = pitch.Pitch('C')
>>> c4 == cImplied
False
>>> c4.ps == cImplied.ps
True

Note: currently spellingIsInferred and fundamental are not checked – this behavior may change in the future.

Pitch.convertMicrotonesToQuarterTones(*, inPlace=False)

Convert any Microtones available to quarter tones, if possible.

>>> p = pitch.Pitch('g3')
>>> p.microtone = 78
>>> str(p)
'G3(+78c)'
>>> p.convertMicrotonesToQuarterTones(inPlace=True)
>>> str(p)
'G#3(-22c)'

>>> p = pitch.Pitch('d#3')
>>> p.microtone = 46
>>> p
<music21.pitch.Pitch D#3(+46c)>
>>> p.convertMicrotonesToQuarterTones(inPlace=True)
>>> p
<music21.pitch.Pitch D#~3(-4c)>

>>> p = pitch.Pitch('f#2')
>>> p.microtone = -38
>>> p.convertMicrotonesToQuarterTones(inPlace=True)
>>> str(p)
'F~2(+12c)'

Pitch.convertQuarterTonesToMicrotones(*, inPlace=False)

Convert any quarter tone Accidentals to Microtones.

tilde is the symbol for half-sharp, so G#~ is G three-quarters sharp.

>>> p = pitch.Pitch('G#~')
>>> str(p), p.microtone
('G#~', <music21.pitch.Microtone (+0c)>)
>>> p.convertQuarterTonesToMicrotones(inPlace=True)
>>> p.ps
68.5
>>> str(p), p.microtone
('G#(+50c)', <music21.pitch.Microtone (+50c)>)

>>> p = pitch.Pitch('A')
>>> p.accidental = pitch.Accidental('half-flat')  # back-tick
>>> str(p), p.microtone
('A`', <music21.pitch.Microtone (+0c)>)
>>> x = p.convertQuarterTonesToMicrotones(inPlace=False)
>>> str(x), x.microtone
('A(-50c)', <music21.pitch.Microtone (-50c)>)
>>> str(p), p.microtone
('A`', <music21.pitch.Microtone (+0c)>)

Pitch.getAllCommonEnharmonics(alterLimit: int = 2) → list[PitchType]

Return all common unique enharmonics for a pitch, or those that do not involve more than two accidentals.

>>> p = pitch.Pitch('c#3')
>>> p.getAllCommonEnharmonics()
[<music21.pitch.Pitch D-3>, <music21.pitch.Pitch B##2>]

“Higher” enharmonics are listed before “Lower”:

>>> p = pitch.Pitch('G4')
>>> p.getAllCommonEnharmonics()
[<music21.pitch.Pitch A--4>, <music21.pitch.Pitch F##4>]

By setting alterLimit to a higher or lower number we can limit the maximum number of notes to return:

>>> p = pitch.Pitch('G-6')
>>> p.getAllCommonEnharmonics(alterLimit=1)
[<music21.pitch.Pitch F#6>]

If you set alterLimit to 3 or 4, you’re stretching the name of the method; some of these are certainly not common enharmonics:

>>> p = pitch.Pitch('G-6')
>>> enharmonics = p.getAllCommonEnharmonics(alterLimit=3)
>>> [str(enh) for enh in enharmonics]
['A---6', 'F#6', 'E##6']

Music21 does not support accidentals beyond quadruple sharp/flat, so alterLimit = 4 is the most you can use. (Thank goodness!)

Pitch.getCentShiftFromMidi() → int

Get cent deviation of this pitch from MIDI pitch.

>>> p = pitch.Pitch('c~4')
>>> p.ps
60.5
>>> p.midi  # midi values automatically round up at 0.5
61
>>> p.getCentShiftFromMidi()
-50
>>> p.microtone = -25
>>> p.ps
60.25
>>> p.midi
60
>>> p.getCentShiftFromMidi()
25

>>> p = pitch.Pitch('c#4')
>>> p.microtone = -25
>>> p.ps
60.75
>>> p.midi
61
>>> p.getCentShiftFromMidi()
-25

>>> p = pitch.Pitch('c#~4')
>>> p.ps
61.5
>>> p.midi
62
>>> p.getCentShiftFromMidi()
-50
>>> p.microtone = -3
>>> p.ps
61.47
>>> p.midi
61
>>> p.getCentShiftFromMidi()
47
>>> p.microtone = 3
>>> p.ps
61.53
>>> p.midi
62
>>> p.accidental
<music21.pitch.Accidental one-and-a-half-sharp>
>>> p.getCentShiftFromMidi()
-47

>>> p = pitch.Pitch('c`4')  # quarter tone flat
>>> p.getCentShiftFromMidi()
-50
>>> p.microtone = 3
>>> p.getCentShiftFromMidi()
-47

Absurd octaves that MIDI can’t handle will still give the right sounding pitch out of octave:

>>> p = pitch.Pitch('c~4')
>>> p.octave = 10
>>> p.ps
132.5
>>> p.midi
121
>>> p.getCentShiftFromMidi()
-50
>>> p.octave = -1
>>> p.getCentShiftFromMidi()
-50
>>> p.octave = -2
>>> p.getCentShiftFromMidi()
-50

Pitch.getEnharmonic(*, inPlace=False) → PitchType | None

Returns a new Pitch that is the(/an) enharmonic equivalent of this Pitch. Can be thought of as flipEnharmonic or something like that.

N.B.: n1.name == getEnharmonic(getEnharmonic(n1)).name is not necessarily true. For instance:

getEnharmonic(E##) => F# getEnharmonic(F#) => G- getEnharmonic(A–) => G getEnharmonic(G) => F##

However, for all cases not involving double sharps or flats (and even many that do), getEnharmonic(getEnharmonic(n)) = n

For the most ambiguous cases, it’s good to know that these are the enharmonics:

C <-> B#, D <-> C##, E <-> F-; F <-> E#, G <-> F##, A <-> B–, B <-> C-

However, isEnharmonic() for A## and B certainly returns True.

>>> p = pitch.Pitch('d#')
>>> print(p.getEnharmonic())
E-
>>> p = pitch.Pitch('e-8')
>>> print(p.getEnharmonic())
D#8

Other tests:

>>> print(pitch.Pitch('c-3').getEnharmonic())
B2
>>> print(pitch.Pitch('e#2').getEnharmonic())
F2
>>> print(pitch.Pitch('f#2').getEnharmonic())
G-2
>>> print(pitch.Pitch('c##5').getEnharmonic())
D5
>>> print(pitch.Pitch('g3').getEnharmonic())
F##3
>>> print(pitch.Pitch('B7').getEnharmonic())
C-8

Octaveless Pitches remain octaveless:

>>> p = pitch.Pitch('a-')
>>> p.getEnharmonic()
<music21.pitch.Pitch G#>
>>> p = pitch.Pitch('B#')
>>> p.getEnharmonic()
<music21.pitch.Pitch C>

Works with half-sharps, but converts them to microtones:

>>> dHalfSharp = pitch.Pitch('D~')
>>> print(dHalfSharp.getEnharmonic())
E-(-50c)

Pitch.getHarmonic(number: int) → Pitch

Return a Pitch object representing the harmonic found above this Pitch.

>>> p = pitch.Pitch('a4')
>>> print(p.getHarmonic(2))
A5
>>> print(p.getHarmonic(3))
E6(+2c)
>>> print(p.getHarmonic(4))
A6
>>> print(p.getHarmonic(5))
C#7(-14c)
>>> print(p.getHarmonic(6))
E7(+2c)
>>> print(p.getHarmonic(7))
F#~7(+19c)
>>> print(p.getHarmonic(8))
A7

>>> p2 = p.getHarmonic(2)
>>> p2
<music21.pitch.Pitch A5>
>>> p2.fundamental
<music21.pitch.Pitch A4>
>>> p2.transpose('p5', inPlace=True)
>>> p2
<music21.pitch.Pitch E6>
>>> p2.fundamental
<music21.pitch.Pitch E5>

Or we can iterate over a list of the next 8 odd harmonics:

>>> allHarmonics = ''
>>> for i in [9, 11, 13, 15, 17, 19, 21, 23]:
...     allHarmonics += ' ' + str(p.getHarmonic(i))
>>> print(allHarmonics)
B7(+4c) D~8(+1c) F~8(-9c) G#8(-12c) B-8(+5c) C9(-2c) C#~9(+21c) E`9(-22c)

Microtonally adjusted notes also generate harmonics:

>>> q = pitch.Pitch('C4')
>>> q.microtone = 10
>>> q.getHarmonic(2)
<music21.pitch.Pitch C5(+10c)>
>>> q.getHarmonic(3)
<music21.pitch.Pitch G5(+12c)>

The fundamental is stored with the harmonic.

>>> h7 = pitch.Pitch('A4').getHarmonic(7)
>>> print(h7)
F#~7(+19c)
>>> h7.fundamental
<music21.pitch.Pitch A4>
>>> h7.harmonicString()
'7thH/A4'
>>> h7.harmonicString('A3')
'14thH/A3'

>>> h2 = h7.getHarmonic(2)
>>> h2
<music21.pitch.Pitch F#~8(+19c)>
>>> h2.fundamental
<music21.pitch.Pitch F#~7(+19c)>
>>> h2.fundamental.fundamental
<music21.pitch.Pitch A4>
>>> h2.transpose(-24, inPlace=True)
>>> h2
<music21.pitch.Pitch F#~6(+19c)>
>>> h2.fundamental.fundamental
<music21.pitch.Pitch A2>

Pitch.getHigherEnharmonic(*, inPlace: Literal[False]) → PitchType

Pitch.getHigherEnharmonic(*, inPlace: Literal[True]) → None

Returns an enharmonic Pitch object that is a higher enharmonic. That is, the Pitch a diminished-second above the current Pitch.

>>> p1 = pitch.Pitch('C#3')
>>> p2 = p1.getHigherEnharmonic()
>>> print(p2)
D-3

We can also set it in place (in which case it returns None):

>>> p1 = pitch.Pitch('C#3')
>>> p1.getHigherEnharmonic(inPlace=True)
>>> print(p1)
D-3

The method even works for certain CRAZY enharmonics

>>> p3 = pitch.Pitch('D--3')
>>> p4 = p3.getHigherEnharmonic()
>>> print(p4)
E----3

But not for things that are just utterly insane:

>>> p4.getHigherEnharmonic()
Traceback (most recent call last):
music21.pitch.AccidentalException: -5 is not a supported accidental type

Note that half accidentals (~ = half-sharp, ` = half-flat) get converted to microtones:

>>> pHalfSharp = pitch.Pitch('D~4')
>>> p3QuartersFlat = pHalfSharp.getHigherEnharmonic()
>>> print(p3QuartersFlat)
E-4(-50c)

Pitch.getLowerEnharmonic(*, inPlace: Literal[False]) → PitchType

Pitch.getLowerEnharmonic(*, inPlace: Literal[True]) → None

returns a Pitch enharmonic that is a diminished second below the current note

If inPlace is set to true, changes the current Pitch and returns None.

>>> p1 = pitch.Pitch('E-')
>>> p2 = p1.getLowerEnharmonic()
>>> print(p2)
D#

The lower enharmonic can have a different octave than the original.

>>> p1 = pitch.Pitch('C-3')
>>> p2 = p1.getLowerEnharmonic()
>>> print(p2)
B2

>>> p1 = pitch.Pitch('C#3')
>>> p1.getLowerEnharmonic(inPlace=True)
>>> print(p1)
B##2

Pitch.getStringHarmonic(chordIn)

Given a chord, determines whether the chord constitutes a string harmonic and then returns a new chord with the proper sounding pitch added.

>>> n1 = note.Note('d3')
>>> n2 = note.Note('g3')
>>> n2.notehead = 'diamond'
>>> n2.noteheadFill = False
>>> p1 = pitch.Pitch('d3')
>>> harmChord = chord.Chord([n1, n2])
>>> harmChord.quarterLength = 1
>>> newChord = p1.getStringHarmonic(harmChord)
>>> newChord.quarterLength = 1
>>> pitchList = newChord.pitches
>>> pitchList
(<music21.pitch.Pitch D3>, <music21.pitch.Pitch G3>, <music21.pitch.Pitch D5>)

otherwise returns False

Pitch.harmonicAndFundamentalFromPitch(target: str | Pitch) → tuple[int, music21.pitch.Pitch]

Given a Pitch that is a plausible target for a fundamental, return the harmonic number and a potentially shifted fundamental that describes this Pitch.

>>> g4 = pitch.Pitch('g4')
>>> g4.harmonicAndFundamentalFromPitch('c3')
(3, <music21.pitch.Pitch C3(-2c)>)

Pitch.harmonicAndFundamentalStringFromPitch(fundamental: str | Pitch) → str

Given a Pitch that is a plausible target for a fundamental, find the harmonic number and a potentially shifted fundamental that describes this Pitch. Return a string representation.

>>> pitch.Pitch('g4').harmonicAndFundamentalStringFromPitch('c3')
'3rdH/C3(-2c)'

>>> pitch.Pitch('c4').harmonicAndFundamentalStringFromPitch('c3')
'2ndH/C3'

>>> p = pitch.Pitch('c4')
>>> p.microtone = 20  # raise 20
>>> p.harmonicAndFundamentalStringFromPitch('c3')
'2ndH/C3(+20c)'

>>> p.microtone = -20  # lower 20
>>> p.harmonicAndFundamentalStringFromPitch('c3')
'2ndH/C3(-20c)'

>>> p = pitch.Pitch('c4')
>>> f = pitch.Pitch('c3')
>>> f.microtone = -20
>>> p.harmonicAndFundamentalStringFromPitch(f)
'2ndH/C3'
>>> f.microtone = +20
>>> p.harmonicAndFundamentalStringFromPitch(f)
'2ndH/C3'

>>> p = pitch.Pitch('A4')
>>> p.microtone = 69
>>> p.harmonicAndFundamentalStringFromPitch('c2')
'7thH/C2'

>>> p = pitch.Pitch('A4')
>>> p.harmonicAndFundamentalStringFromPitch('c2')
'7thH/C2(-69c)'

Pitch.harmonicFromFundamental(fundamental: str | Pitch) → tuple[int, float]

Given another Pitch as a fundamental, find the harmonic of that pitch that is equal to this Pitch.

Returns a tuple of harmonic number and the number of cents that the first Pitch object would have to be shifted to be the exact harmonic of this fundamental.

Microtones applied to the fundamental are irrelevant, as the fundamental may be microtonally shifted to find a match to this Pitch.

Example: G4 is the third harmonic of C3, albeit 2 cents flatter than the true 3rd harmonic.

>>> p = pitch.Pitch('g4')
>>> f = pitch.Pitch('c3')
>>> p.harmonicFromFundamental(f)
(3, 2.0)
>>> p.microtone = p.harmonicFromFundamental(f)[1]  # adjust microtone
>>> int(f.getHarmonic(3).frequency) == int(p.frequency)
True

The shift from B-5 to the 7th harmonic of C3 is more substantial and likely to be noticed by the audience. To make p the 7th harmonic it’d have to be lowered by 31 cents. Note that the second argument is a float, but because the default rounding of music21 is to the nearest cent, the 0.0 is not a significant digit. I.e. it might be more like 31.3 cents.

>>> p = pitch.Pitch('B-5')
>>> f = pitch.Pitch('C3')
>>> p.harmonicFromFundamental(f)
(7, -31.0)

Pitch.harmonicString(fundamental: str | Pitch | None = None) → str

Return a string representation of a harmonic equivalence.

N.B. this has nothing to do with what string a string player would use to play the harmonic on. (Perhaps should be renamed).

>>> pitch.Pitch('g4').harmonicString('c3')
'3rdH(-2c)/C3'

>>> pitch.Pitch('c4').harmonicString('c3')
'2ndH/C3'

>>> p = pitch.Pitch('c4')
>>> p.microtone = 20  # raise 20
>>> p.harmonicString('c3')
'2ndH(+20c)/C3'

>>> p.microtone = -20  # lower 20
>>> p.harmonicString('c3')
'2ndH(-20c)/C3'

>>> p = pitch.Pitch('c4')
>>> f = pitch.Pitch('c3')
>>> f.microtone = -20
>>> p.harmonicString(f)
'2ndH(+20c)/C3(-20c)'
>>> f.microtone = +20
>>> p.harmonicString(f)
'2ndH(-20c)/C3(+20c)'

>>> p = pitch.Pitch('A4')
>>> p.microtone = 69
>>> p.harmonicString('c2')
'7thH/C2'

>>> p = pitch.Pitch('A4')
>>> p.harmonicString('c2')
'7thH(-69c)/C2'

Pitch.informClient()

if this pitch is attached to a note, then let it know that it has changed.

Pitch.isEnharmonic(other: Pitch) → bool

Return True if another Pitch is an enharmonic equivalent of this Pitch.

>>> p1 = pitch.Pitch('C#3')
>>> p2 = pitch.Pitch('D-3')
>>> p3 = pitch.Pitch('D#3')
>>> p1.isEnharmonic(p2)
True
>>> p2.isEnharmonic(p1)
True
>>> p3.isEnharmonic(p1)
False

Pitches are enharmonics of themselves:

>>> pC = pitch.Pitch('C4')
>>> pC.isEnharmonic(pC)
True

Notes that sound in different octaves are not enharmonics:

>>> pitch.Pitch('C#4').isEnharmonic( pitch.Pitch('D-5') )
False

However, different octave numbers can be the same enharmonic, because octave number is relative to the step (natural form) of the pitch.

>>> pitch.Pitch('C4').isEnharmonic( pitch.Pitch('B#3') )
True
>>> pitch.Pitch('C4').isEnharmonic( pitch.Pitch('B#4') )
False

If either pitch is octaveless, then a pitch in any octave will match:

>>> pitch.Pitch('C#').isEnharmonic( pitch.Pitch('D-9') )
True
>>> pitch.Pitch('C#4').isEnharmonic( pitch.Pitch('D-') )
True

Quarter tone enharmonics work as well:

>>> pC.accidental = pitch.Accidental('one-and-a-half-sharp')
>>> pC
<music21.pitch.Pitch C#~4>
>>> pD = pitch.Pitch('D4')
>>> pD.accidental = pitch.Accidental('half-flat')
>>> pD
<music21.pitch.Pitch D`4>
>>> pC.isEnharmonic(pD)
True

Microtonally altered pitches do not return True unless the microtones are the same:

>>> pSharp = pitch.Pitch('C#4')
>>> pSharp.microtone = 20
>>> pFlat = pitch.Pitch('D-4')
>>> pSharp.isEnharmonic(pFlat)
False

>>> pFlat.microtone = 20
>>> pSharp.isEnharmonic(pFlat)
True

Extreme enharmonics also work:

>>> p4 = pitch.Pitch('B##3')
>>> p5 = pitch.Pitch('E---4')
>>> p4.isEnharmonic(p5)
True

If either pitch has no octave then the comparison is done without regard to octave:

>>> pSharp4 = pitch.Pitch('C#4')
>>> pFlatNoOctave = pitch.Pitch('D-')
>>> pSharp4.isEnharmonic(pFlatNoOctave)
True
>>> pFlatNoOctave.isEnharmonic(pSharp4)
True

isEnharmonic can be combined with a test to see if two pitches have the same step to ensure that they both sound the same and are written the same, without regard to the presence or absence of an accidental (this is used in :meth:~music21.stream.base.Stream.stripTies):

>>> pD4 = pitch.Pitch('D4')
>>> pDNatural4 = pitch.Pitch('D4', accidental=pitch.Accidental('natural'))
>>> pD4 == pDNatural4
False
>>> pD4.isEnharmonic(pDNatural4) and pD4.step == pDNatural4.step
True
>>> pEbb4 = pitch.Pitch('E--4')
>>> pD4.isEnharmonic(pEbb4) and pD4.step == pEbb4.step
False

Pitch.isTwelveTone() → bool

Return True if this Pitch is one of the twelve tones available on a piano keyboard. Returns False if it instead has a non-zero microtonal adjustment or has a quarter tone accidental.

>>> p = pitch.Pitch('g4')
>>> p.isTwelveTone()
True
>>> p.microtone = -20
>>> p.isTwelveTone()
False

>>> p2 = pitch.Pitch('g~4')
>>> p2.isTwelveTone()
False

Pitch.simplifyEnharmonic(*, inPlace=False, mostCommon=False) → PitchType | None

Returns a new Pitch (or sets the current one if inPlace is True) that is either the same as the current pitch or has fewer sharps or flats if possible. For instance, E# returns F, while A# remains A# (i.e., does not take into account that B- is more common than A#). Useful to call if you ever have an algorithm that might take your piece far into the realm of double or triple flats or sharps.

If mostCommon is set to True, then the most commonly used enharmonic spelling is chosen (that is, the one that appears first in key signatures as you move away from C on the circle of fifths). Thus, G-flat becomes F#, A# becomes B-flat, D# becomes E-flat, D-flat becomes C#, G# and A-flat are left alone.

>>> p1 = pitch.Pitch('B#5')
>>> p1.simplifyEnharmonic().nameWithOctave
'C6'

>>> p2 = pitch.Pitch('A#2')
>>> p2.simplifyEnharmonic(inPlace=True)
>>> p2
<music21.pitch.Pitch A#2>

>>> p3 = pitch.Pitch('E--3')
>>> p4 = p3.transpose(interval.Interval('-A5'))
>>> p4.simplifyEnharmonic()
<music21.pitch.Pitch F#2>

Setting mostCommon = True simplifies enharmonics even further.

>>> pList = [pitch.Pitch('A#4'), pitch.Pitch('B-4'),
...          pitch.Pitch('G-4'), pitch.Pitch('F#4')]
>>> [str(p.simplifyEnharmonic(mostCommon=True)) for p in pList]
['B-4', 'B-4', 'F#4', 'F#4']

Note that pitches with implicit octaves retain their implicit octaves. This might change the pitch space for B#s and C-s.

>>> pList = [pitch.Pitch('B'), pitch.Pitch('C#'), pitch.Pitch('G'), pitch.Pitch('A--')]
>>> [str(p.simplifyEnharmonic()) for p in pList]
['B', 'C#', 'G', 'G']

>>> pList = [pitch.Pitch('C-'), pitch.Pitch('B#')]
>>> [p.ps for p in pList]
[59.0, 72.0]
>>> [p.simplifyEnharmonic().ps for p in pList]
[71.0, 60.0]

Pitch.transpose(value: IntervalBase | str | int, *, inPlace: Literal[True]) → None

Pitch.transpose(value: IntervalBase | str | int, *, inPlace: Literal[False] = False) → PitchType

Transpose the pitch by the user-provided value. If the value is an integer, the transposition is treated in half steps. If the value is a string, any Interval string specification can be provided. Alternatively, a music21.interval.Interval object can be supplied.

>>> aPitch = pitch.Pitch('g4')
>>> bPitch = aPitch.transpose('m3')
>>> bPitch
<music21.pitch.Pitch B-4>
>>> cPitch = bPitch.transpose(interval.GenericInterval(2))
>>> cPitch
<music21.pitch.Pitch C-5>

An interval object can also be a certain number of semitones, in which case, the spelling of the resulting note (sharp or flat, etc.) is up to the system to choose.

>>> aInterval = interval.Interval(-6)
>>> bPitch = aPitch.transpose(aInterval)
>>> bPitch
<music21.pitch.Pitch C#4>

Transpose fFlat down 5 semitones – sort of like a Perfect 4th, but should be respelled:

>>> fFlat = pitch.Pitch('F-4')
>>> newPitch = fFlat.transpose(-5)
>>> newPitch
<music21.pitch.Pitch B3>

>>> aPitch
<music21.pitch.Pitch G4>

>>> aPitch.transpose(aInterval, inPlace=True)
>>> aPitch
<music21.pitch.Pitch C#4>

Implicit octaves remain implicit:

>>> anyGSharp = pitch.Pitch('G#')
>>> print(anyGSharp.transpose('P8'))
G#
>>> print(anyGSharp.transpose('P5'))
D#

If the accidental of a pitch is chosen by music21, not given by the user, then after transposing, music21 will simplify the spelling again:

>>> pc6 = pitch.Pitch(6)
>>> pc6
<music21.pitch.Pitch F#>
>>> pc6.spellingIsInferred
True
>>> pc6.transpose('-m2')
<music21.pitch.Pitch F>

Pitch.transposeAboveTarget(target, *, minimize=False, inPlace=False) → PitchType | None

Given a source Pitch, shift it up octaves until it is above the target.

If minimize is True, a pitch above the target will move down to the nearest octave.

>>> pitch.Pitch('d2').transposeAboveTarget(pitch.Pitch('e4'))
<music21.pitch.Pitch D5>

To change the pitch itself, set inPlace to True:

>>> p = pitch.Pitch('d2')
>>> p.transposeAboveTarget(pitch.Pitch('e4'), inPlace=True)
>>> p
<music21.pitch.Pitch D5>

If already above the target, make no change:

>>> pitch.Pitch('d7').transposeAboveTarget(pitch.Pitch('e2'))
<music21.pitch.Pitch D7>

Accept the same pitch:

>>> pitch.Pitch('d2').transposeAboveTarget(pitch.Pitch('d8'))
<music21.pitch.Pitch D8>

If minimize is True, we go the closest position:

>>> pitch.Pitch('d#8').transposeAboveTarget(pitch.Pitch('d2'), minimize=True)
<music21.pitch.Pitch D#2>

>>> pitch.Pitch('d7').transposeAboveTarget(pitch.Pitch('e2'), minimize=True)
<music21.pitch.Pitch D3>

>>> pitch.Pitch('d0').transposeAboveTarget(pitch.Pitch('e2'), minimize=True)
<music21.pitch.Pitch D3>

If the original pitch is octaveless, raises a PitchException:

>>> pitch.Pitch('d').transposeAboveTarget(pitch.Pitch('e2'), minimize=True)
Traceback (most recent call last):
music21.pitch.PitchException: Cannot call transposeAboveTarget with an octaveless Pitch.

If the target pitch is octaveless, assumes it has the default of octave 4. (The reason for this asymmetry is that the target pitch is never altered while the original pitch (or its copy) is).

>>> pitch.Pitch('d4').transposeAboveTarget(pitch.Pitch('e'), minimize=True)
<music21.pitch.Pitch D5>

• Changed in v3: default for inPlace=False.

Pitch.transposeBelowTarget(target, *, minimize=False, inPlace=False) → PitchType | None

Given a source Pitch, shift it down some number of octaves until it is below the target.

If minimize is True, a pitch below the target will move up to the nearest octave.

>>> higherG = pitch.Pitch('G5')
>>> lowerG = higherG.transposeBelowTarget(pitch.Pitch('C#4'))
>>> lowerG
<music21.pitch.Pitch G3>
>>> higherG
<music21.pitch.Pitch G5>

To change the pitch itself, set inPlace to True:

>>> p = pitch.Pitch('G5')
>>> p.transposeBelowTarget(pitch.Pitch('C#4'), inPlace=True)
>>> p
<music21.pitch.Pitch G3>

If already below the target, make no change:

>>> pitch.Pitch('G#3').transposeBelowTarget(pitch.Pitch('C#6'))
<music21.pitch.Pitch G#3>

Below target includes being the same as the target

>>> pitch.Pitch('g#8').transposeBelowTarget(pitch.Pitch('g#1'))
<music21.pitch.Pitch G#1>

This does nothing because it is already low enough:

>>> pitch.Pitch('g#2').transposeBelowTarget(pitch.Pitch('f#8'))
<music21.pitch.Pitch G#2>

But with minimize=True, it will actually RAISE the pitch so that it is the closest pitch to the target

>>> target = pitch.Pitch('f#8')
>>> pitch.Pitch('g#2').transposeBelowTarget(target, minimize=True)
<music21.pitch.Pitch G#7>

>>> pitch.Pitch('f#2').transposeBelowTarget(target, minimize=True)
<music21.pitch.Pitch F#8>

If the original pitch is octaveless, raises a PitchException:

>>> pitch.Pitch('d').transposeBelowTarget(pitch.Pitch('e2'), minimize=True)
Traceback (most recent call last):
music21.pitch.PitchException: Cannot call transposeBelowTarget with an octaveless Pitch.

If the target pitch is octaveless, assumes it has the default of octave 4. (The reason for this asymmetry is that the target pitch is never altered while the original pitch (or its copy) is).

>>> pitch.Pitch('f4').transposeBelowTarget(pitch.Pitch('e'), minimize=True)
<music21.pitch.Pitch F3>

• Changed in v3: default for inPlace=False.

Pitch.updateAccidentalDisplay(*, pitchPast: list[music21.pitch.Pitch] | None = None, pitchPastMeasure: list[music21.pitch.Pitch] | None = None, otherSimultaneousPitches: list[music21.pitch.Pitch] | None = None, alteredPitches: list[music21.pitch.Pitch] | None = None, cautionaryPitchClass: bool = True, cautionaryAll: bool = False, overrideStatus: bool = False, cautionaryNotImmediateRepeat: bool = True, lastNoteWasTied: bool = False)

Given an ordered list of Pitch objects in pitchPast, determine if this pitch’s Accidental object needs to be created or updated with a natural or other cautionary accidental.

Changes to this Pitch object’s Accidental object are made in-place.

pitchPast is a list of pitches preceding this pitch in the same measure. If None, a new list will be made.

pitchPastMeasure is a list of pitches preceding this pitch but in a previous measure. If None, a new list will be made.

otherSimultaneousPitches is a list of other pitches in this simultaneity, for use when cautionaryPitchClass is True.

The alteredPitches list supplies pitches from a KeySignature object using the alteredPitches property. If None, a new list will be made.

If cautionaryPitchClass is True, comparisons to past accidentals are made regardless of register. That is, if a past sharp is found two octaves above a present natural, a natural sign is still displayed. Note that this has nothing to do with whether a sharp (not in the key signature) is found in a different octave from the same note in a different octave. The sharp must always be displayed. Notes with displayType = ‘if-absolutely-necessary’ will ignore the True setting.

If overrideStatus is True, this method will ignore any current displayStatus setting found on the Accidental. By default, this does not happen. If displayStatus is set to None, the Accidental’s displayStatus is set.

If cautionaryNotImmediateRepeat is True, cautionary accidentals will be displayed for an altered pitch even if that pitch had already been displayed as altered (unless it’s an immediate repetition). Notes with displayType = ‘if-absolutely-necessary’ will ignore the True setting.

If lastNoteWasTied is True then this note will be treated as immediately following a tie.

>>> a = pitch.Pitch('a')
>>> past = [pitch.Pitch('a#'), pitch.Pitch('c#'), pitch.Pitch('c')]
>>> a.updateAccidentalDisplay(pitchPast=past, cautionaryAll=True)
>>> a.accidental, a.accidental.displayStatus
(<music21.pitch.Accidental natural>, True)

>>> b = pitch.Pitch('a')
>>> past = [pitch.Pitch('a#'), pitch.Pitch('c#'), pitch.Pitch('c')]
>>> b.updateAccidentalDisplay(pitchPast=past)  # should add a natural
>>> b.accidental, b.accidental.displayStatus
(<music21.pitch.Accidental natural>, True)

In this example, the method will not add a natural because the match is pitchSpace and our octave is different.

>>> a4 = pitch.Pitch('a4')
>>> past = [pitch.Pitch('a#3'), pitch.Pitch('c#'), pitch.Pitch('c')]
>>> a4.updateAccidentalDisplay(pitchPast=past, cautionaryPitchClass=False)
>>> a4.accidental is None
True

v8 – made keyword-only and added otherSimultaneousPitches.

Methods inherited from ProtoM21Object:

isClassOrSubclass()

Pitch instance variables

Pitch.spellingIsInferred

Returns True or False about whether enharmonic spelling Has been inferred on pitch creation or whether it has been specified directly.

MIDI 61 is C# or D- equally.

>>> p = pitch.Pitch('C4')
>>> p.spellingIsInferred
False
>>> p.ps = 61
>>> p.spellingIsInferred
True
>>> p.name
'C#'
>>> p.name = 'C#'
>>> p.spellingIsInferred
False

This makes a difference in transposing. For instance:

>>> pInferred = pitch.Pitch(61)
>>> pNotInferred = pitch.Pitch('C#4')
>>> pInferred.nameWithOctave, pNotInferred.nameWithOctave
('C#4', 'C#4')
>>> pInferred.spellingIsInferred, pNotInferred.spellingIsInferred
(True, False)

>>> inferredTransposed = pInferred.transpose('A1')
>>> inferredTransposed.nameWithOctave
'D4'
>>> notInferredTransposed = pNotInferred.transpose('A1')
>>> notInferredTransposed.nameWithOctave
'C##4'

An operation like diatonic transposition should retain the spelling is inferred for the resulting object

>>> inferredTransposed.spellingIsInferred, notInferredTransposed.spellingIsInferred
(True, False)

But Chromatic transposition can change an object to inferred spelling:

>>> p3 = notInferredTransposed.transpose(1)  # C## -> E- not to C###
>>> p3.nameWithOctave
'E-4'
>>> p3.spellingIsInferred
True

Accidental

class music21.pitch.Accidental(specifier: int | str | float = 'natural')

Accidental class, representing the symbolic and numerical representation of pitch deviation from a pitch name (e.g., G, B).

Two accidentals are considered equal if their names are equal.

Accidentals have three defining attributes: a name, a modifier, and an alter. For microtonal specifications, the name and modifier are the same except in the case of half-sharp, half-flat, one-and-a-half-flat, and one-and-a-half-sharp.

Accidentals up to quadruple-sharp and quadruple-flat are allowed.

Natural-sharp etc. (for canceling a previous flat) are not yet supported officially.

>>> a = pitch.Accidental('sharp')
>>> a.name, a.alter, a.modifier
('sharp', 1.0, '#')
>>> a.style.color = 'red'

>>> import copy
>>> b = copy.deepcopy(a)
>>> b.style.color
'red'

Accidental bases

• ProtoM21Object

• StyleMixin

• SlottedObjectMixin

Accidental read-only properties

Accidental.fullName

Return the most complete representation of this Accidental.

>>> a = pitch.Accidental('double-flat')
>>> a.fullName
'double-flat'

Note that non-standard microtone names are converted to standard ones:

>>> a = pitch.Accidental('quarter-flat')
>>> a.fullName
'half-flat'

For now this is the same as .name.

Accidental.unicode

Return a unicode representation of this accidental or the best unicode representation if that is not possible.

>>> flat = pitch.Accidental('flat')
>>> flat.unicode
'♭'

Compare:

>>> sharp = pitch.Accidental('sharp')
>>> sharp.modifier
'#'
>>> sharp.unicode
'♯'

Some accidentals, such as double sharps, produce code points outside the 2-byte set (so called “astral plane” unicode) and thus cannot be used in every circumnstance.

>>> sharp = pitch.Accidental('quadruple-flat')
>>> sharp.unicode
'𝄫𝄫'

Read-only properties inherited from ProtoM21Object:

classSet

classes

Read-only properties inherited from StyleMixin:

hasEditorialInformation

hasStyleInformation

Accidental read/write properties

Accidental.alter

Get or set the alter of the Accidental, or the semitone shift caused by the Accidental where 1.0 is a shift up of one semitone, and -1.0 is the shift down of one semitone.

>>> sharp = pitch.Accidental('sharp')
>>> sharp.alter
1.0

>>> sharp.alter = -1

After changing alter to a known other value, name changes:

>>> sharp.name
'flat'

But changing it to an unusual value does not change the name:

>>> notSoFlat = pitch.Accidental('flat')
>>> notSoFlat.alter = -0.9
>>> notSoFlat.name
'flat'

• Changed in v5: changing the alter here changes other values, conditionally

Accidental.displayStatus

Determines if this Accidental is to be displayed; can be None (for not set), True, or False. In general do not set this, set .displayType instead. Music21 will change displayStatus at any time without warning.

While .displayType gives general rules about when this accidental should be displayed or not, displayStatus determines whether after applying those rules this accidental will be displayed.

In general, a displayStatus of None means that no high-level processing of accidentals has happened.

Can be set to True or False (or None) directly for contexts where the next program down the line cannot evaluate displayType. See stream.makeAccidentals() for more information.

Example:

>>> n0 = note.Note('C#4')
>>> n1 = note.Note('C#4')
>>> print(n0.pitch.accidental.displayStatus)
None
>>> print(n1.pitch.accidental.displayStatus)
None
>>> s = stream.Stream()
>>> s.append([n0, n1])
>>> s.makeAccidentals(inPlace=True)
>>> n0.pitch.accidental.displayStatus
True
>>> n1.pitch.accidental.displayStatus
False

>>> n1.pitch.accidental.displayStatus = 2
Traceback (most recent call last):
music21.pitch.AccidentalException: Supplied display status is not supported: 2

Accidental.displayType

Returns or sets the display type of the accidental

“normal” (default) displays it if it is the first in measure, or is needed to contradict a previous accidental, etc.

other valid terms:

• “always”

• “never”

• “unless-repeated” (show always unless the immediately preceding note is the same)

• “even-tied” (stronger than always: shows even if it is tied to the previous note)

• “if-absolutely-necessary” (display only if it is absolutely necessary, like an F-natural after an F-sharp in the same measure, but not an F-natural following an F-sharp directly across a barline. Nor an F-natural in a different octave immediately following an F-sharp). This is not yet implemented.

>>> a = pitch.Accidental('flat')
>>> a.displayType = 'unless-repeated'
>>> a.displayType
'unless-repeated'
>>> a.displayType = 'underwater'
Traceback (most recent call last):
music21.pitch.AccidentalException: Supplied display type is not supported: 'underwater'

Accidental.modifier

Get or set the alter of the modifier, or the string symbol used to modify the pitch name, such as “#” or “-” for sharp and flat, respectively. For a representation likely to be read by non-music21 users, see .unicode.

>>> f = pitch.Accidental('flat')
>>> f.modifier
'-'
>>> f.modifier = '#'
>>> f.name
'sharp'

However, an unknown modifier does not change anything but is preserved:

>>> f.modifier = '&'
>>> f.modifier
'&'
>>> f.name
'sharp'

• Changed in v5: changing the modifier here changes other values, conditionally

Accidental.name

Get or set the name of the Accidental, like ‘sharp’ or ‘double-flat’

If the name is set to a standard name then it changes alter and modifier.

If set to a non-standard name, then it does not change them:

>>> a = pitch.Accidental()
>>> a.name = 'flat'
>>> a.alter
-1.0
>>> a.modifier
'-'
>>> a.name = 'flat-flat-up'
>>> a.alter
-1.0

• Changed in v5: changing the name here changes other values, conditionally

Read/write properties inherited from StyleMixin:

editorial

style

Accidental methods

Accidental.__eq__(other)

Equality. Needed for pitch comparisons.

>>> a = pitch.Accidental('double-flat')
>>> b = pitch.Accidental('double-flat')
>>> c = pitch.Accidental('double-sharp')
>>> a == b
True

>>> a == c
False

Accidental.inheritDisplay(other)

Given another Accidental object, inherit all the display properties of that object.

This is needed when transposing Pitches: we need to retain accidental display properties.

>>> a = pitch.Accidental('double-flat')
>>> a.displayType = 'always'
>>> b = pitch.Accidental('sharp')
>>> b.inheritDisplay(a)
>>> b.displayType
'always'

Accidental.isTwelveTone()

Return a boolean if this Accidental describes a twelve-tone, non-microtonal pitch.

>>> a = pitch.Accidental('half-flat')
>>> a.isTwelveTone()
False

>>> a = pitch.Accidental('###')
>>> a.isTwelveTone()
True

classmethod Accidental.listNames()

Returns a list of accidental names that have any sort of semantic importance in music21.

You may choose a name not from this list (1/7th-sharp) but if it’s not on this list don’t expect it to do anything for you.

This is a class method, so you may call it directly on the class:

Listed in alphabetical order. (TODO: maybe from lowest to highest or something implying importance?)

>>> pitch.Accidental.listNames()
 ['double-flat', 'double-sharp', 'flat', 'half-flat',
  'half-sharp', 'natural', 'one-and-a-half-flat', 'one-and-a-half-sharp',
  'quadruple-flat', 'quadruple-sharp', 'sharp', 'triple-flat', 'triple-sharp']

Or call on an instance of an accidental:

>>> f = pitch.Accidental('flat')
>>> f.listNames()
 ['double-flat', 'double-sharp', 'flat', 'half-flat', 'half-sharp', 'natural',
  'one-and-a-half-flat', 'one-and-a-half-sharp', 'quadruple-flat', 'quadruple-sharp',
  'sharp', 'triple-flat', 'triple-sharp']

Accidental.set(name, *, allowNonStandardValue=False)

Change the type of the Accidental. Strings, numbers, and Lilypond (German-like) abbreviations are all accepted. All other values will change after setting.

>>> a = pitch.Accidental()
>>> a.set('sharp')
>>> a.alter
1.0

>>> a = pitch.Accidental()
>>> a.set(2)
>>> a.modifier == '##'
True

>>> a = pitch.Accidental()
>>> a.set(2.0)
>>> a.modifier == '##'
True

>>> a = pitch.Accidental('--')
>>> a.alter
-2.0
>>> a.set('half-sharp')
>>> a.alter
0.5
>>> a.name
'half-sharp'

Setting an illegal name is generally an error:

>>> a.set('flat-flat-up')
Traceback (most recent call last):
music21.pitch.AccidentalException: flat-flat-up is not a supported accidental type

But if ‘allowNonStandardValue’ is True then other names (if strings) or alters (if numbers) are allowed:

>>> a.set('quintuple-sharp', allowNonStandardValue=True)
>>> a.set(5.0, allowNonStandardValue=True)
>>> a.name
'quintuple-sharp'
>>> a.alter
5.0

This is the argument that .name and .alter use to allow non-standard names

• Changed in v5: added allowNonStandardValue

Accidental.setAttributeIndependently(attribute, value)

Set an attribute of ‘name’, ‘alter’, and ‘modifier’, independently of the other attributes.

>>> a = pitch.Accidental('natural')
>>> a.setAttributeIndependently('alter', 1.0)
>>> a.alter
1.0
>>> a.name
'natural'

>>> a.setAttributeIndependently('name', 'sori')
>>> a.setAttributeIndependently('modifier', '$')
>>> a.modifier
'$'
>>> a.name
'sori'
>>> a.alter
1.0

Only ‘name’, ‘alter’, and ‘modifier’ can be set independently:

>>> a.setAttributeIndependently('color', 'red')
Traceback (most recent call last):
music21.pitch.AccidentalException: Cannot set attribute color independently of other parts.

• New in v5: needed because .name, .alter, and .modifier run .set()

Methods inherited from ProtoM21Object:

isClassOrSubclass()

Accidental instance variables

Accidental.displayLocation

Location of accidental: “normal”, “above”, “below”.

Accidental.displaySize

Size in display: “cue”, “large”, or a percentage.

Accidental.displayStyle

Style of display: “parentheses”, “bracket”, “both”.

Microtone

class music21.pitch.Microtone(centsOrString: str | int | float = 0, harmonicShift=1)

The Microtone object defines a pitch transformation above or below a standard Pitch and its Accidental.

>>> m = pitch.Microtone(20)
>>> m.cents
20

>>> m.alter
0.2...

>>> print(m)
(+20c)
>>> m
<music21.pitch.Microtone (+20c)>

Microtones can be shifted according to the harmonic. Here we take the 3rd harmonic of the previous microtone

>>> m.harmonicShift = 3
>>> m.harmonicShift
3
>>> m
<music21.pitch.Microtone (+20c+3rdH)>

>>> m.cents
1922

>>> m.alter
19.2...

Microtonal changes can be positive or negative. Both Positive and negative numbers can optionally be placed in parentheses Negative numbers in parentheses still need the minus sign.

>>> m = pitch.Microtone('(-33.333333)')
>>> m
<music21.pitch.Microtone (-33c)>

>>> m = pitch.Microtone('33.333333')
>>> m
<music21.pitch.Microtone (+33c)>

Note that we round the display of microtones to the nearest cent, but we keep the exact alteration in both .cents and .alter:

>>> m.cents
33.333...

>>> m.alter
0.3333...

Microtone bases

• ProtoM21Object

• SlottedObjectMixin

Microtone read-only properties

Microtone.alter

Return the microtone value in accidental alter values.

>>> pitch.Microtone(20).alter
0.2

Microtone.cents

Return the microtone value in cents. This is not a settable property. To set the value in cents, simply use that value as a creation argument.

>>> pitch.Microtone(20).cents
20

Read-only properties inherited from ProtoM21Object:

classSet

classes

Microtone read/write properties

Microtone.harmonicShift

Set or get the harmonic shift, altering the microtone

Microtone methods

Microtone.__eq__(other)

Compare cents (including harmonicShift)

>>> m1 = pitch.Microtone(20)
>>> m2 = pitch.Microtone(20)
>>> m3 = pitch.Microtone(21)
>>> m1 == m2
True
>>> m1 == m3
False

>>> m2.harmonicShift = 3
>>> m1 == m2
False

Cannot compare True to a non-Microtone:

>>> m1 == pitch.Accidental(1)
False

Methods inherited from ProtoM21Object:

isClassOrSubclass()

Functions

music21.pitch.convertPitchClassToStr(pc: int) → str

Given a pitch class number, return a string.

>>> pitch.convertPitchClassToStr(3)
'3'
>>> pitch.convertPitchClassToStr(10)
'A'

music21.pitch.isValidAccidentalName(name: str) → bool

Check if name is a valid accidental name string that can be used to initialize an Accidental.

Standard accidental names are valid:

>>> pitch.isValidAccidentalName('double-flat')
True

Accidental modifiers are valid:

>>> pitch.isValidAccidentalName('--')
True

Alternate accidental names are valid:

>>> pitch.isValidAccidentalName('eses')
True

Anything else is not valid:

>>> pitch.isValidAccidentalName('two flats')
False

music21.pitch.simplifyMultipleEnharmonics(pitches, criterion=<function _dissonanceScore>, keyContext=None)

Tries to simplify the enharmonic spelling of a list of pitches, pitch- or pitch-class numbers according to a given criterion.

A function can be passed as an argument to criterion, that is tried to be minimized in a greedy left-to-right fashion.

>>> pitch.simplifyMultipleEnharmonics([11, 3, 6])
[<music21.pitch.Pitch B>, <music21.pitch.Pitch D#>, <music21.pitch.Pitch F#>]

>>> pitch.simplifyMultipleEnharmonics([3, 8, 0])
[<music21.pitch.Pitch E->, <music21.pitch.Pitch A->, <music21.pitch.Pitch C>]

>>> pitch.simplifyMultipleEnharmonics([pitch.Pitch('G3'),
...                                    pitch.Pitch('C-4'),
...                                    pitch.Pitch('D4')])
[<music21.pitch.Pitch G3>, <music21.pitch.Pitch B3>, <music21.pitch.Pitch D4>]

>>> pitch.simplifyMultipleEnharmonics([pitch.Pitch('A3'),
...                                    pitch.Pitch('B#3'),
...                                    pitch.Pitch('E4')])
[<music21.pitch.Pitch A3>, <music21.pitch.Pitch C4>, <music21.pitch.Pitch E4>]

The attribute keyContext is for supplying a KeySignature or a Key which is used in the simplification:

>>> pitch.simplifyMultipleEnharmonics([6, 10, 1], keyContext=key.Key('B'))
[<music21.pitch.Pitch F#>, <music21.pitch.Pitch A#>, <music21.pitch.Pitch C#>]

>>> pitch.simplifyMultipleEnharmonics([6, 10, 1], keyContext=key.Key('C-'))
[<music21.pitch.Pitch G->, <music21.pitch.Pitch B->, <music21.pitch.Pitch D->]

Note that if there’s no key context, then we won’t simplify everything (at least for now; this behavior may change, ).

>>> pitch.simplifyMultipleEnharmonics([pitch.Pitch('D--3'),
...                                    pitch.Pitch('F-3'),
...                                    pitch.Pitch('A--3')])
[<music21.pitch.Pitch D--3>, <music21.pitch.Pitch F-3>, <music21.pitch.Pitch A--3>]

>>> pitch.simplifyMultipleEnharmonics([pitch.Pitch('D--3'),
...                                    pitch.Pitch('F-3'),
...                                    pitch.Pitch('A--3')],
...                                    keyContext=key.Key('C'))
[<music21.pitch.Pitch C3>, <music21.pitch.Pitch E3>, <music21.pitch.Pitch G3>]

• Changed in v7.3: fixed a bug with compound intervals (such as formed against the tonic of a KeySignature defaulting to octave 4):

>>> pitch.simplifyMultipleEnharmonics([pitch.Pitch('B5')], keyContext=key.Key('D'))
[<music21.pitch.Pitch B5>]

music21.pitch.standardizeAccidentalName(name: str) → str

Convert a valid accidental name to the standard accidental name. Raises AccidentalException if name is not a valid accidental name.

>>> pitch.standardizeAccidentalName('double-flat')
'double-flat'

>>> pitch.standardizeAccidentalName('--')
'double-flat'

>>> pitch.standardizeAccidentalName('eses')
'double-flat'

>>> pitch.standardizeAccidentalName('two flats')
Traceback (most recent call last):
music21.pitch.AccidentalException: 'two flats' is not a supported accidental type