Abjad follows the following pitch conventions.
Abjad names pitches according to the LilyPond english.ly module.
Abjad names accidentals according to the table below.
accidental symbol quarter sharp ‘qs’ quarter flat ‘qf’ sharp ‘s’ flat ‘f’ three-quarters sharp ‘tqs’ three-quarters flat ‘tqf’ double sharp ‘ss’ double flat ‘ff’
Abjad sets middle C equal to 0. This follows the presentation of American pitch-class theory in, for example, [Morris1987] .
IRCAM / MIDI pitch numbers equal Abjad pitch numbers plus 60.
Abjad represents octaves with both numbers and ticks.
Octave notation Tick notation C7 c’‘’‘ C6 c’‘’ C5 c’‘ C4 c’ C3 c C2 c, C1 c,,
Abjad follows American usage and sets the octave of middle C equal to 4. usage.
Abjad uses ticks in LilyPond output only.
Abjad chooses between enharmonic spellings at pitch-initialization time according to the following table.
PC number Default spelling 0 C 1 C♯ 2 D 3 E♭ 4 E 5 F 6 F♯ 7 G 8 G♭ 9 A 10 B♭ 11 B
For example:
abjad> t = Staff([Note(n, (1, 8)) for n in range(12)])
abjad> print t.format
\new Staff {
c'8
cs'8
d'8
ef'8
e'8
f'8
fs'8
g'8
af'8
a'8
bf'8
b'8
}
You can use pitchtools.make_sharp() and pitchtools.make_flat() to respell accidentals after initialization:
abjad> pitchtools.make_sharp(t)
abjad> print t.format
\new Staff {
c'8
cs'8
d'8
ds'8
e'8
f'8
fs'8
g'8
gs'8
a'8
as'8
b'8
}