The Kyma Language for Sound Design, Version 4.5

Event Values
Even though the GenericSource program is permanently running on the Capybara, we still only hear the
sample once because the Trigger is an unchanging constant. § How can we control the value of Trigger?
One way would be for Kyma to watch for incoming MIDI keyboard events, setting the value of
Trigger to 1 when the key is down and 0 when the key goes up. ‡
To specify that the Trigger should come from MIDI key down:
1. Click or Tab into the Trigger field
2. Press the Escape key on your computer keyboard (the cursor changes to a little fader)
3. Play two keys at once on your MIDI keyboard
Play the GenericSource and try triggering it with the MIDI keyboard. Try changing the ReleaseTime to
50 ms, play the GenericSource, and play the keyboard again. AttackTime and ReleaseTime provide a
simple amplitude envelope on the GenericSource to avoid on/off clicks.
A red name that starts with an exclamation point (like !KeyDown, above) is called an Event Value. An
Event Value is not a constant, like an ordinary number. Instead, it relies on external events for its value.
These external events include: pressing a MIDI keyboard key, moving a MIDI fader, sending out MIDI
events from a software sequencer, moving a fader in Kyma’s virtual control surface, generating events
algorithmically using the MIDIVoice or AnalogSequencer Sounds, or even writing your own C programs
to set these Event Values as if they were variables in your program.
An Event Value can change while the Sound is playing, unlike a constant value which is set once when
the Sound first starts up.
Playing this monotone harp GenericSource begs the question, how can you control Frequency from the
keyboard? The steps are almost the same:
1. Click or tab into the Frequency field
2. Press Escape once (do not hold it down)
3. Play a single key on the MIDI keyboard
§ Sounds that have Trigger fields are triggered whenever the Trigger becomes positive. To trigger the Sound
again, the Trigger has to become zero or negative, then positive again.
‡ If you haven’t already done so, now is the time to connect the output of your MIDI keyboard and/or other controllers
directly to the MIDI in jack on the back of the Capybara. To make sure that you are receiving MIDI, use
Configure MIDI… (found under the DSP menu); it has an option to display all incoming MIDI events.
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