Steve Reich’s Clapping Music

In this example, we will use some of auxjad’s classes and functions to generate the score of Steve Reich’s Clapping Music.

First, we start by importing both abjad and auxjad.

>>> import abjad
>>> import auxjad

Let’s now input the basic material that will be used to generate this composition. The original score is notated using a rhythmic staff, so we can initialise abjad.Staff with the property lilypond_type set to "RhythmicStaff".

>>> material = abjad.Staff(r"\time 12/8 c8 c c r c c r c r c c r",
...                        lilypond_type="RhythmicStaff",
...                        )
>>> abjad.show(material)

Next, we create an instance of auxjad.Phaser which will be used to create the phasing process of the initial material. We initialise it with material as well as a step_size of the length of a quaver.

>>> phaser = auxjad.Phaser(material,
...                        step_size=abjad.Duration((1, 8)),
...                        )

Since Reich’s composition phases the material until it is back at its initial position, we can use the method output_all() to generate all thirtee measures of the bottom staff.

>>> notes = phaser.output_all()
>>> phased_staff = abjad.Staff(notes,
...                            lilypond_type="RhythmicStaff",
...                            )
>>> abjad.show(phased_staff)

The upper staff of the composition consists of thirteen measures of the material being repeated. We can thus use the class auxjad.Repeater() to generate these repetitions and take care of removing the time signatures of the repeated measures.

>>> repeater = auxjad.Repeater(material)
>>> notes = repeater(13)
>>> constant_staff = abjad.Staff(notes,
...                              lilypond_type="RhythmicStaff",
...                              )
>>> abjad.show(constant_staff)

With both staves created, we can now add them to a single score.

>>> score = abjad.Score([constant_staff, phased_staff])
>>> abjad.show(score)

We now group the leaves of the upper staff by measures and add a double repetition bar line to the last leaf of each measure. The very last leaf of the score should have a single end repetition bar line.

>>> measures = abjad.select(constant_staff[:]).group_by_measure()
>>> for measure in measures[:-1]:
...     abjad.attach(abjad.BarLine(':..:'), measure[-1])
>>> abjad.attach(abjad.BarLine(':|.'), constant_staff[-1])
>>> abjad.show(score)