pitchtypes.spelled.SpelledPitchClass

class pitchtypes.spelled.SpelledPitchClass(value)

Bases: Spelled, AbstractSpelledPitch, AbstractPitch

Represents a spelled pitch class, i.e. a pitch without octave information.

__init__(value)

Takes a string consisting of the form <letter><accidentals?>, e.g. "C#", "E", or "Dbb". 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 class

Methods

__init__(value)

Takes a string consisting of the form <letter><accidentals?>, e.g. "C#", "E", or "Dbb".

alteration()

Return the number of semitones by which the interval is altered from its perfect or major variant.

compare(other)

Comparison between two spelled pitch classes according to line-of-fifth.

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(fifths)

Create a pitch class by directly providing its position on the line of fifths (C=0, G=1, D=2, ...).

from_onehot(onehot, fifth_low)

Create a spelled pitch class from a one-hot vector.

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_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.

name()

The name of the pitch or interval in string notation

octaves()

For intervals, return the number of octaves the interval spans.

onehot(fifth_range[, dtype])

Returns a one-hot encoding of the pitch class in fifths.

parse_interval(s)

Parse a string as a spelled interval or spelled interval class.

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

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)

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

__getattr__(item)

This method is called when an attribute is not found in the instance’s __dict__. It allows to access the linked Pitch, Interval, PitchClass, and IntervalClass types via the base type.

__gt__(other)

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

__hash__ = None
__le__(other)

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).

__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

alteration()

Return the number of semitones by which the interval is altered from its 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 pitch classes according to line-of-fifth.

Returns 0 if the pitch classes are equal, 1 if the first pitch class (self) is greater (“sharper”), and -1 if the second pitch class (other) is greater (“sharper”).

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

Parameters:

other – a pitch class to compare to (SpelledPitchClass)

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(fifths)

Create a pitch class by directly providing its position on the line of fifths (C=0, G=1, D=2, …).

Parameters:

fifths – the line-of-fifths position of the pitch class (integer)

Returns:

the resulting pitch class (SpelledPitchClass)

static from_onehot(onehot, fifth_low)

Create a spelled pitch class from a one-hot vector.

Requires the lower bounds of the fifth range used by the one-hot vector.

Parameters:

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

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

Returns:

the resulting pitch class (SpelledPitchClass)

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)

A decorator to link an interval class type to its base type. :type skip_name_check: bool :param skip_name_check: skip the name check and don’t raise :type create_init: Optional[bool] :param create_init: if True, create a default __init__ method :type create_add: Optional[bool] :param create_add: if True, create a default __add__ method :type create_sub: Optional[bool] :param create_sub: if True, create a default __sub__ method :type create_mul: Optional[bool] :param create_mul: if True, create a default __mul__ method :type create_div: Optional[bool] :param create_div: if True, create a default __truediv__ method :type create_neg: Optional[bool] :param create_neg: if True, create a default __neg__ method :meta private:

A decorator to link an interval type to its base type. :type skip_name_check: bool :param skip_name_check: skip the name check and don’t raise :type create_init: Optional[bool] :param create_init: if True, create a default __init__ method :type create_add: Optional[bool] :param create_add: if True, create a default __add__ method :type create_sub: Optional[bool] :param create_sub: if True, create a default __sub__ method :type create_mul: Optional[bool] :param create_mul: if True, create a default __mul__ method :type create_div: Optional[bool] :param create_div: if True, create a default __truediv__ method :type create_neg: Optional[bool] :param create_neg: if True, create a default __neg__ method :type create_to_class: Optional[bool] :param create_to_class: if True, create a default to_class method :meta private:

A decorator to link a pitch class type to its base type. :type skip_name_check: bool :param skip_name_check: skip the name check and don’t raise :type create_init: Optional[bool] :param create_init: if True, create a default __init__ method :type create_add: Optional[bool] :param create_add: if True, create a default __add__ method :type create_sub: Optional[bool] :param create_sub: if True, create a default __sub__ method :return: a decorator that links the pitch class type to the base type :meta private:

A decorator to link a pitch type to its base type. :type skip_name_check: bool :param skip_name_check: skip the name check and don’t raise :type create_init: Optional[bool] :param create_init: if True, create a default __init__ method :type create_add: Optional[bool] :param create_add: if True, create a default __add__ method :type create_sub: Optional[bool] :param create_sub: if True, create a default __sub__ method :type create_to_class: Optional[bool] :param create_to_class: if True, create a default to_class method :meta private:

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, dtype=<class 'int'>)

Returns a one-hot encoding of the pitch class in fifths. The range of fifths is given by fifth_range as a tuple (lower, upper).

Parameters:

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

  • dtype – dtype of the resulting array

Returns:

a one-hot vector (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

to_class()

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

Returns:

the pitch class that corresponds to this pitch