The Kyma Language for Sound Design, Version 4.5

MIDIVoice Scripts
The MIDIVoice and MIDIMapper modules give you three choices for the source of MIDI events: the live
MIDI input stream (originating with external controllers or a sequencer or other software running in parallel
with Kyma), a MIDI file stored on disk, or a MIDI script (which generates MIDI events
algorithmically and then emits them).
These examples illustrate some of the tools for algorithmically generating MIDI events using the Script
parameter of a MIDIVoice or MIDIMapper. For more information about MIDI event scripts, see MIDI
Scripts beginning on page 522.
Notes and Controllers
Notes
The syntax for a basic note-on event is:
self keyDownAt: aTime duration: aDur frequency: aFreq velocity: 0To1.
When you drop the velocity tag, the event defaults to a velocity of 1.
Transcription of Short Sequences
Take a look at (and compile, load, start) machautKyrie to see a simple application of these note events:
direct transcription of written notation by hand into MIDI script events. For short note sequences, entering
the events by hand is often the quickest and most straightforward way to do it. Here is an excerpt
from the Machaut example:
MM := 90.
"------------------------------------"
self keyDownAt: 0 beats duration: 3 beats frequency: 4 a.
self keyDownAt: 3 beats duration: 1 beat frequency: 4 a.
self keyDownAt: 4 beats duration: 1 beat frequency: 4 b.
self keyDownAt: 5 beats duration: 1 beat frequency: 4 g.
self keyDownAt: 6 beats duration: 2 beats frequency: 4 a.
self keyDownAt: 8 beats duration: 0.5 beats frequency: 4 f.
self keyDownAt: 8.5 beats duration: 0.5 beats frequency: 4 e.
(and so on…)
The first line of this script informs Kyma of the metronome that should be used to define the beat for the
rest of the script. The remaining lines are a transcription of each note from the piece.
Modulo Arithmetic
The script of a MIDIVoice or MIDIMapper is actually a program written in Smalltalk; this means that you
can generate events according to an algorithm. The script in Kurt’s new rhythm method illustrates the use
of modulo arithmetic in an algorithm that creates a kind of twisted drum machine.
In this script, a subset of seven different fixed-duration fixed-frequency events is algorithmically selected
for scheduling on each beat. The following is an outline of the script:
MM := 300.
0 to: 200 do: [ :i |
(a series of omitted event selection decisions)
].
The first line of the script sets the metronome. The rest of the script is a loop that counts the variable i up
from 0 to 200. Inside the loop, a series of decisions are made to determine whether each of the seven possible
events should be scheduled for this beat.
The first of the seven event decisions is:
i \\ 4 = 0 ifTrue: [
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