5.6. LilyPond multipliers

LilyPond provides an asterisk * operator to scale the durations of notes, rests and chords by arbitrarily positive rational values. LilyPond multipliers are inivisible and generate no typographic output of their own. However, while independent from the typographic output, LilyPond multipliers do factor in in calculations of duration and time.

Abjad implements LilyPond multpliers as the settable duration.multiplier attribute of notes, rests and chords.

abjad> note = Note("c'4")
abjad> note.duration_multiplier = Fraction(1, 2)
abjad> note.duration_multiplier
Fraction(1, 2)

abjad> f(note)
c'4 * 1/2

Abjad also implements a duration.multiplied attribute to examine the duration of a note, rest or chord as affected by the multiplier.

abjad> note.multiplied_duration
Duration(1, 8)

LilyPond multipliers give the half notes here multiplied durations equal to a quarter note.

abjad> notes = Note("c'4") * 4
abjad> multiplied_note = Note(0, (1, 2))
abjad> multiplied_note.duration_multiplier = Fraction(1, 2)
abjad> multiplied_notes = multiplied_note * 4
abjad> top = stafftools.RhythmicStaff(notes)
abjad> bottom = stafftools.RhythmicStaff(multiplied_notes)
abjad> staves = scoretools.StaffGroup([top, bottom])

Note

Abjad models multiplication fundamentally differently than prolation . See the chapter on Prolation for more information.

Note

The LilyPond multiplication * operator differs from the Abjad multiplication * operator. LilyPond multiplication scales duration of LilyPond notes, rests and chords. Abjad multiplication copies Abjad containers and leaves.