Welcome

Abjad helps composers build up complex pieces of music notation in iterative and incremental ways. Use Abjad to create a symbolic representation of all the notes, rests, chords, tuplets, beams and slurs in any score. Because Abjad extends the Python programming language, you can use Abjad to make systematic changes to music as you work. Because Abjad wraps the LilyPond music notation package, you can use Abjad to control the typographic detail of symbols on the page.

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Abjad requires Python 3.10 and LilyPond 2.23.6 (or later).

Make sure LilyPond is installed: http://lilypond.org/development.html

Create a Python 3 virtual environment for Abjad: https://docs.python.org/3/tutorial/venv.html

Activate the virtual environment and then use pip to install Abjad:

~$ python -m pip install abjad

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As a first example, start Python, import Abjad, make some notes:

>>> import abjad
>>> string = "c'16 f' g' a' d' g' a' b' e' a' b' c'' f' b' c'' d''16"
>>> voice_1 = abjad.Voice(string, name="Voice_1")
>>> staff_1 = abjad.Staff([voice_1], name="Staff_1")
>>> abjad.show(staff_1)

Use Python’s list operations to split, reverse, join the input string. Then extend voice 1:

>>> pitches = string.split()
>>> pitches = reversed(pitches)
>>> retrograde = " ".join(pitches)
>>> voice_1.extend(retrograde)
>>> abjad.show(staff_1)

Create a second voice in a second staff:

>>> string = string + " " + retrograde
>>> voice_2 = abjad.Voice(string, name="Voice_2")
>>> staff_2 = abjad.Staff([voice_2], name="Staff_2")

Enclose both staves in a staff group and a score:

>>> piano_staff = abjad.StaffGroup(
...     [staff_1, staff_2],
...     lilypond_type="PianoStaff",
...     name="PianoStaff",
... )
>>> score = abjad.Score([piano_staff], name="Score")
>>> abjad.show(score)

Invert the pitches in voice 2:

>>> for note in abjad.select.notes(voice_2):
...     note.written_pitch = note.written_pitch.invert(axis="G4")
... 
>>> abjad.show(score)

Define a function to partition notes, loop over parts, attach slurs, attach articulations:

>>> def slur_parts(voice, counts):
...     notes = abjad.select.notes(voice)
...     parts = abjad.select.partition_by_counts(notes, counts, cyclic=True)
...     for part in parts:
...         first_note, last_note = part[0], part[-1]
...         accent = abjad.Articulation("accent")
...         start_slur = abjad.StartSlur()
...         abjad.attach(accent, first_note)
...         abjad.attach(start_slur, first_note)
...         staccato = abjad.Articulation("staccato")
...         stop_slur = abjad.StopSlur()
...         abjad.attach(staccato, last_note)
...         abjad.attach(stop_slur, last_note)
... 

Slur voice 1:

>>> slur_parts(voice_1, [2, 4, 4])
>>> abjad.show(score)

Slur voice 2:

>>> slur_parts(voice_2, [4])
>>> abjad.show(score)

Define a function to tupletize alternating groups of notes:

>>> def tupletize_notes(voice, counts, modulus):
...     notes = abjad.select.notes(voice)
...     parts = abjad.select.partition_by_counts(notes, counts, cyclic=True)
...     for i, part in enumerate(parts):
...         if i % len(counts) == modulus:
...             abjad.mutate.wrap(part, abjad.Tuplet("3:2"))
... 

Tupletize voice 1:

>>> tupletize_notes(voice_1, [6, 4], 0)
>>> abjad.show(score)

Tupletize voice 2:

>>> tupletize_notes(voice_2, [4, 6], 1)
>>> abjad.show(score)

Trim both voices:

>>> del voice_1[-6:]
>>> del voice_2[-3:]
>>> abjad.show(score)

Attach a time signature, attach a doule bar line, clean up tuplet brackets:

>>> first_note = abjad.select.note(voice_1, 0)
>>> time_signature = abjad.TimeSignature((2, 8))
>>> abjad.attach(time_signature, first_note)
>>> last_note = abjad.select.note(voice_2, -1)
>>> bar_line = abjad.BarLine("|.")
>>> abjad.attach(bar_line, last_note)
>>> abjad.override(score).tuplet_bracket.staff_padding = 2
>>> abjad.show(score)

Read Abjad’s docs using the table of contents to the left. Happy composing and welcome to Abjad!