"""Music21 input interface."""
from typing import Dict, List, Tuple, Union
from music21.instrument import partitionByInstrument
from music21.stream import Opus, Part, Score, Stream
from ..classes import (
Chord,
KeySignature,
Metadata,
Note,
Tempo,
TimeSignature,
Track,
)
from ..music import DEFAULT_RESOLUTION, Music
def parse_metadata(stream: Stream) -> Union[Metadata, None]:
"""Return metadata parsed from a music21 Stream object.
Parameters
----------
stream : `music21.stream.Stream`
Stream object to parse.
Returns
-------
:class:`muspy.Metadata`
Parsed metadata.
"""
if stream.metadata is None:
return None
creators = []
for contributor in stream.metadata.contributors:
creators.extend(contributor.names)
copyright_ = None
for item in stream.metadata.all(skipContributors=True):
if item[0] == "copyright":
copyright_ = item[1]
return Metadata(
title=stream.metadata.title, creators=creators, copyright=copyright_,
)
def parse_tempos(stream: Stream, resolution=DEFAULT_RESOLUTION) -> List[Tempo]:
"""Return tempos parsed from a music21 Stream object.
Parameters
----------
stream : `music21.stream.Stream`
Stream object to parse.
resolution : int, optional
Time steps per quarter note. Defaults to
`muspy.DEFAULT_RESOLUTION`.
Returns
-------
list of :class:`muspy.Tempo`
Parsed tempos.
"""
tempos = []
for start, _, metronome in stream.flat.metronomeMarkBoundaries():
time = int(float(start * resolution))
tempo = Tempo(time, metronome.getQuarterBPM())
tempos.append(tempo)
return tempos
def parse_key_signatures(
stream: Stream, resolution=DEFAULT_RESOLUTION
) -> List[KeySignature]:
"""Return key signatures parsed from a music21 Stream object.
Parameters
----------
stream : `music21.stream.Stream`
Stream object to parse.
resolution : int, optional
Time steps per quarter note. Defaults to
`muspy.DEFAULT_RESOLUTION`.
Returns
-------
list of :class:`muspy.KeySignature`
Parsed key signatures.
"""
key_signatures = []
for item in stream.flat.getElementsByClass("Key"):
time = int(float(item.offset * resolution))
key_signature = KeySignature(time, item.tonic.pitchClass, item.mode)
key_signatures.append(key_signature)
return key_signatures
def parse_time_signatures(
stream: Stream, resolution=DEFAULT_RESOLUTION
) -> List[TimeSignature]:
"""Return time signatures parsed from a music21 Stream object.
Parameters
----------
stream : `music21.stream.Stream`
Stream object to parse.
resolution : int, optional
Time steps per quarter note. Defaults to
`muspy.DEFAULT_RESOLUTION`.
Returns
-------
list of :class:`muspy.TimeSignature`
Parsed time signatures.
"""
time_signatures = []
for item in stream.flat.getTimeSignatures():
time = int(float(item.offset * resolution))
time_signature = TimeSignature(time, item.numerator, item.denominator)
time_signatures.append(time_signature)
return time_signatures
def parse_notes_and_chords(
stream: Stream, resolution=DEFAULT_RESOLUTION
) -> Tuple[List[Note], List[Chord]]:
"""Return notes and chords parsed from a music21 Stream object.
Parameters
----------
stream : `music21.stream.Stream`
Stream object to parse.
resolution : int, optional
Time steps per quarter note. Defaults to
`muspy.DEFAULT_RESOLUTION`.
Returns
-------
list of :class:`muspy.Note`
Parsed notes.
list of :class:`muspy.Chord`
Parsed chords.
"""
notes: List[Note] = []
chords: List[Chord] = []
ties: Dict[int, int] = {}
for item in stream.flat.notesAndRests:
# Ignore rests
if not item.isNote and not item.isChord:
continue
# Ignore grace notes
if item.duration.isGrace:
continue
# Parse note
time = int(round(float(item.offset * resolution)))
duration = int(round(float(item.quarterLength) * resolution))
if item.isNote:
pitch = int(item.pitch.midi)
is_outgoing_tie = item.tie and (
item.tie.type == "start" or item.tie.type == "continue"
)
if pitch in ties:
note_idx = ties[pitch]
notes[note_idx].duration += duration
if is_outgoing_tie:
ties[pitch] = note_idx
else:
del ties[pitch]
else:
note = Note(
time=time, pitch=int(item.pitch.midi), duration=duration
)
notes.append(note)
if is_outgoing_tie:
ties[pitch] = len(notes) - 1
elif item.isChord:
pitches = [note.pitch.midi for note in item.notes]
chord = Chord(time=time, pitches=pitches, duration=duration)
chords.append(chord)
return notes, chords
def parse_track(part: Part, resolution=DEFAULT_RESOLUTION) -> Track:
"""Return track parsed from a music21 Part object.
Parameters
----------
part : `music21.stream.Part`
Part object to parse.
resolution : int, optional
Time steps per quarter note. Defaults to
`muspy.DEFAULT_RESOLUTION`.
Returns
-------
:class:`muspy.Track`
Parsed track.
"""
notes, chords = parse_notes_and_chords(part, resolution)
instrument = part.getInstrument()
if instrument.midiProgram is not None:
program = instrument.midiProgram
else:
program = 0
if instrument.midiChannel is not None:
is_drum = instrument.midiChannel == 10
else:
is_drum = False
return Track(
program=program,
is_drum=is_drum,
name=part.partName,
notes=notes,
chords=chords,
)
def from_music21_part(
part: Part, resolution=DEFAULT_RESOLUTION
) -> Union[Track, List[Track]]:
"""Return a music21 Part object as Track object(s).
Parameters
----------
part : `music21.stream.Part`
Part object to parse.
resolution : int, optional
Time steps per quarter note. Defaults to
`muspy.DEFAULT_RESOLUTION`.
Returns
-------
:class:`muspy.Track` or list of :class:`muspy.Track`
Parsed track(s).
"""
instruments = partitionByInstrument(part)
if not instruments:
return parse_track(part, resolution)
return [parse_track(instrument, resolution) for instrument in instruments]
def from_music21_score(score: Score, resolution=DEFAULT_RESOLUTION) -> Music:
"""Return a music21 Stream object as a Music object.
Parameters
----------
score : `music21.stream.Score`
Score object to convert.
resolution : int, optional
Time steps per quarter note. Defaults to
`muspy.DEFAULT_RESOLUTION`.
Returns
-------
:class:`muspy.Music`
Converted Music object.
"""
tracks = []
for part in score.parts:
instruments = partitionByInstrument(part)
if instruments:
for instrument in instruments:
tracks.append(parse_track(instrument))
elif len(part.flat.notesAndRests) > 0:
tracks.append(parse_track(part))
return Music(
metadata=parse_metadata(score),
resolution=DEFAULT_RESOLUTION,
tempos=parse_tempos(score),
key_signatures=parse_key_signatures(score, resolution),
time_signatures=parse_time_signatures(score, resolution),
tracks=tracks,
)
[docs]def from_music21_opus(
opus: Opus, resolution=DEFAULT_RESOLUTION
) -> List[Music]:
"""Return a music21 Opus object as a list of Music objects.
Parameters
----------
opus : `music21.stream.Opus`
Opus object to convert.
resolution : int, optional
Time steps per quarter note. Defaults to
`muspy.DEFAULT_RESOLUTION`.
Returns
-------
:class:`muspy.Music`
Converted Music object.
"""
return [from_music21_score(score, resolution) for score in opus.scores]
[docs]def from_music21(
stream: Stream, resolution=DEFAULT_RESOLUTION
) -> Union[Music, List[Music], Track, List[Track]]:
"""Return a music21 Stream object as Music or Track object(s).
Parameters
----------
stream : `music21.stream.Stream`
Stream object to convert.
resolution : int, optional
Time steps per quarter note. Defaults to
`muspy.DEFAULT_RESOLUTION`.
Returns
-------
:class:`muspy.Music` or :class:`muspy.Track`
Converted Music or Track object(s).
"""
if isinstance(stream, Opus):
return from_music21_opus(stream, resolution)
elif isinstance(stream, Part):
return from_music21_part(stream, resolution)
else:
return from_music21_score(stream, resolution)
tracks = []
if isinstance(stream, Score):
for part in stream.parts:
instruments = partitionByInstrument(part)
if instruments:
for instrument in instruments:
tracks.append(parse_track(instrument))
elif len(part.flat.notesAndRests) > 0:
tracks.append(parse_track(part))
else:
instruments = partitionByInstrument(stream)
if instruments:
for instrument in instruments:
tracks.append(parse_track(instrument))
elif len(stream.flat.notesAndRests) > 0:
tracks.append(parse_track(stream))
return Music(
metadata=parse_metadata(stream),
resolution=DEFAULT_RESOLUTION,
tempos=parse_tempos(stream),
key_signatures=parse_key_signatures(stream, resolution),
time_signatures=parse_time_signatures(stream, resolution),
tracks=tracks,
)