pitchtypes.spelled.SpelledPitch

class pitchtypes.spelled.SpelledPitch(value)

Bases: Spelled, AbstractSpelledPitch, Pitch

Represents a spelled pitch.

__init__(value)

Takes a string consisting of the form <letter><accidentals?><octave>, e.g. "C#4", "E5", or "Db-2". Accidentals may be written as ASCII symbols (#/b) or with unicode symbols (♯/♭), but not mixed within the same note.

Parameters:

value – a string or internal numeric representation of the pitch

Methods

__init__(value)	Takes a string consisting of the form <letter><accidentals?><octave>, e.g. "C#4", "E5", or "Db-2".
alteration()	Return the number of semitones by which the interval is altered from its the perfect or major variant.
compare(other)	Comparison between two spelled pitches according to diatonic ordering.
convert_to(other_type)
create_subtypes()
degree()	Return the "relative scale degree" (0-6) to which the interval points (unison=0, 2nd=1, octave=0, 2nd down=6, etc.).
embed()	For a pitch class, returns the corresponding pitch in a (type-dependent) default octave.
fifths()	Return the position of the interval on the line of fifths.
from_fifths_and_octaves(fifths, octaves)	Create a pitch by directly providing its internal fifths and octaves.
from_independent(fifths, octaves)	Create a pitch from fifths (pitch class) and independent/external octaves (octave number).
from_onehot(onehot, fifth_low, octave_low)	Create a spelled pitch from a one-hot matrix.
generic_interval_class_from_fifths(fifth_steps)	Return the generic interval class corresponding to the given number of fifths.
internal_octaves()	Return the internal octave representation of a pitch, which is dependent on the fifths.
interval_class_from_fifths(fifths[, inverse])	Return the interval class corresponding to the given number of steps along the line of fifths.
interval_from(other)	Computes the interval from another pitch to this pitch.
interval_quality_from_fifths(fifth_steps)	Return the interval quality (major, minor, perfect, augmented, diminished, doubly-augmented etc) given the number of steps along the line of fifths.
interval_to(other)	Computes the interval from this pitch to another pitch.
letter()	Returns the letter associated with the pitch (without accidentals).
link_interval_class_type([skip_name_check, ...])	A decorator to link an interval class type to its base type.
link_interval_type([skip_name_check, ...])	A decorator to link an interval type to its base type.
link_pitch_class_type([skip_name_check, ...])	A decorator to link a pitch class type to its base type.
link_pitch_type([skip_name_check, ...])	A decorator to link a pitch type to its base type.
midi()	Return the MIDI value, in the interval [0,127].
name()	The name of the pitch or interval in string notation
name_check(cls, sub_type, suffix, ...)	Check if sub_type follows the standard naming convention.
octaves()	For intervals, return the number of octaves the interval spans.
onehot(fifth_range, octave_range[, dtype])	Returns a one-hot encoding of the pitch in fifths (first dimension) and external octaves (second dimension).
parse_pitch(s)	Parse a string as a spelled pitch or spelled pitch class.
pc()	Returns the pitch class corresponding to the pitch.
pitch_class_from_fifths(fifth_steps)	Return the pitch class given the number of steps along the line of fifths
semitones()	Return the number of chromatic semitones corresponding to the pitch.
set_func_attr(sub_type, flags, names, funcs)	Add functions funcs as methods with names to class sub_type, controlled by flags.
steps()	Return the number of diatonic steps corresponding to the pitch.
to_class()	Alias for pc(), but also supported by interval types.

Interval

alias of SpelledInterval

IntervalClass

alias of SpelledIntervalClass

Pitch

alias of SpelledPitch

PitchClass

alias of SpelledPitchClass

__add__(other)

Returns the pitch transposed by an interval

Parameters:

other – an interval of matching type

Returns:

the pitch transposed by other

__eq__(other)

Return self==value.

__ge__(other, NotImplemented=NotImplemented)

Return a >= b. Computed by @total_ordering from (not a < b).

__gt__(other, NotImplemented=NotImplemented)

Return a > b. Computed by @total_ordering from (not a < b) and (a != b).

__hash__ = None

__le__(other, NotImplemented=NotImplemented)

Return a <= b. Computed by @total_ordering from (a < b) or (a == b).

__lt__(other)

Return self<value.

__repr__()

Return repr(self).

__setattr__(key, value)

Implement setattr(self, name, value).

__str__()

Return str(self).

__sub__(other)

When subtracting another pitch (p1 - p2), return the interval from p2 to p1. When subtracting an interval (p - i), transpose the pitch by the inverse interval (p + -i).

Parameters:

other – pitch or interval

Returns:

if other is an interval, the transposed pitch; if other is a pitch, the interval between both pitches

__weakref__

list of weak references to the object (if defined)

alteration()

Return the number of semitones by which the interval is altered from its the perfect or major variant. Positive alteration always indicates augmentation, negative alteration indicates diminution (minor or smaller) of the interval. For pitches, return the accidentals (positive=sharps, negative=flats, 0=natural).

Returns:

alteration (integer)

compare(other)

Comparison between two spelled pitches according to diatonic ordering.

Returns 0 if the objects are equal, 1 if the first pitch (self) is higher, and -1 if the second pitch (other) is higher.

This method can be indirectly used through binary comparison operators (including ==, < etc.).

Parameters:

other – a pitch to compare to (SpelledPitch)

Returns:

-1 / 0 / 1 (integer)

degree()

Return the “relative scale degree” (0-6) to which the interval points (unison=0, 2nd=1, octave=0, 2nd down=6, etc.). For pitches, return the integer that corresponds to the letter (C=0, D=1, …).

Returns:

degree (integer)

embed()

For a pitch class, returns the corresponding pitch in a (type-dependent) default octave. For non-class pitches, returns the pitch itself.

Returns:

a non-class version of this pitch

fifths()

Return the position of the interval on the line of fifths.

Returns:

fifth position (integer)

static from_fifths_and_octaves(fifths, octaves)

Create a pitch by directly providing its internal fifths and octaves.

Each pitch is represented relative to C0 by moving the specified number of fifths and octaves upwards (or downwards for negative values).

Parameters:

• fifths – the fifth (= pitch class) of the pitch (integer)

• octaves – the internal/dependent octave of the pitch (integer)

Returns:

the resulting pitch (SpelledPitch)

static from_independent(fifths, octaves)

Create a pitch from fifths (pitch class) and independent/external octaves (octave number).

Parameters:

• fifths – the fifth (= pitch class) of the pitch (integer)

• octaves – the external/independent octave of the pitch (integer)

Returns:

the resulting pitch (SpelledPitch)

static from_onehot(onehot, fifth_low, octave_low)

Create a spelled pitch from a one-hot matrix.

Requires the lower bounds of the fifth and octave range used by the one-hot matrix.

Parameters:

• onehot – a one-hot matrix representing the pitch (numpy array)

• fifth_low – the lowest fifth expressible in the one-hot matrix

• octave_low – the lowest octave expressible in the one-hot matrix

Returns:

the resulting pitch (SpelledPitch)

internal_octaves()

Return the internal octave representation of a pitch, which is dependent on the fifths.

Only use this if you know what you are doing.

Returns:

internal/dependent octave (integer)

interval_from(other)

Computes the interval from another pitch to this pitch.

Parameters:

other – another pitch

Returns:

the interval from other to self

interval_to(other)

Computes the interval from this pitch to another pitch.

Parameters:

other – another pitch

Returns:

the interval from self to other

letter()

Returns the letter associated with the pitch (without accidentals).

Returns:

letter (single-character string)

midi()

Return the MIDI value, in the interval [0,127].

Returns:

MIDI value (integer)

name()

The name of the pitch or interval in string notation

Returns:

the object’s notation name (string)

octaves()

For intervals, return the number of octaves the interval spans. Negative intervals start with -1, decreasing. For pitches, return the absolute octave of the pitch.

Returns:

external/independent octave (integer)

onehot(fifth_range, octave_range, dtype=<class 'int'>)

Returns a one-hot encoding of the pitch in fifths (first dimension) and external octaves (second dimension). The range of fifths and octaves is given by fifth_range and octave_range respectively, where each is a pair (lower, upper).

Parameters:

• fifth_range – the (inclusive) range of fifths (pair of integers)

• octave_range – the (inclusive) range of octaves (pair of integers)

• dtype – dtype of the resulting array

Returns:

a one-hot matrix (numpy array)

pc()

Returns the pitch class corresponding to the pitch. For pitch classes, it returns the pitch class itself.

Returns:

the pitch class that corresponds to this pitch

semitones()

Return the number of chromatic semitones corresponding to the pitch.

steps()

Return the number of diatonic steps corresponding to the pitch.

to_class()

Alias for pc(), but also supported by interval types.

Returns:

the pitch class that corresponds to this pitch