The Kyma Language for Sound Design, Version 4.5

Sampling On-the-fly
You can record live sounds in to the Capybara RAM with one Sound and play them back with another.
For example, play the Sound called live scrambulation. When the GenericSource asks for the source,
press Enter to use the default source (a recording stored on the disk). This Sound writes the recording
into Capybara RAM and then reads out of Capybara RAM using four Samples with random loop starts.
Try different settings for !Length — the length of the Sample loops.
Now play live scrambulation again, but this time, set the GenericSource to use the live input and try
singing, speaking, whistling, and making other mouth noises into the microphone. Whenever you exceed
the !Threshold amplitude, six seconds of the microphone input is captured in RAM. You can see how
long you have to record by watching the !TimeLeft fader. Then if you remain quiet enough not to trigger
another recording, the Samples will continue to loop on whatever was captured the first time. Each
time you exceed the threshold, it will record over the previous six second recording. Play with this for a
while, trying different length settings and different kinds of vocal noises.
Then double-click live scrambulation to see how it is put together: After the Annotation and Preset (the
sine qua non of any well-documented Kyma example!) there is a Mixer called record live input & chop.
True to its name, one branch of this Mixer records the input into RAM, and the other branch of the Mixer
reads out of that same RAM with random loop points.
Double-click on record when threshold exceeded to see its parameters. Its RecordingName is set to recording,
its CaptureDuration is 6 s, and it is triggered by a Sound called TimeLeftAndTrigger (which
we will examine more closely in a moment).
Compare that to the parameters of one of the four Samples called ReadMem that feed into the StereoMix4
called 4 chopped samples. This is a Sample that reads out of the same memory that the MemoryWriter
writes into. Its Sample is set to recording (the same name as the RecordingName parameter in the
MemoryWriter). Whenever you want to read out of the RAM that is being written into by a different
Sound, you must check the FromMemoryWriter box in the Sound that is reading the memory; that way,
Kyma knows not to bother looking for that sample or wavetable on disk but to look for it in another part
of the same Sound. Notice also that the LoopStart of the sample comes from Noise and that the
LoopEnd comes from that same Noise generator plus one tenth the value of !Length. Notice that we
had to take the absolute value of the Noise because the output of Noise is in the range of (-1,1) and
LoopStart expects values in the range of (0,1).
Now take a look at the Sound called TimeLeft & Trigger, the trigger for the MemoryWriter. This is a
SoundToEvent module — a Sound that generates Event Values. The Event Values generated by a
SoundToEvent look, to all the other Sounds, the same as if they had come in from the MIDI input. In this
particular instance, the value to be generated is given by the expression:
| inputTrigger outputTriggerDuration |
"The trigger to start our trigger and how long it should be on."
inputTrigger := env follower L threshold: (!Threshold * 0.1).
outputTriggerDuration := 6 s.
1 - (inputTrigger * (1 - !TimeLeft asLogicValue)
ramp: outputTriggerDuration)
This is a somewhat twisted way of saying that the MemoryWriter should be triggered when the amplitude
envelope of the GenericSource exceeds some threshold, and that it should record for six seconds
without allowing another triggering during that time.
By the way, this is an advanced example of how one can combine Event Values and expressions, so if it
doesn’t make total sense to you immediately, don’t feel discouraged at this early stage. Just come back to
look at it again later after you have had more experience with Event Values and Smalltalk programming.
If you do understand it at this early stage then call us up and tell us so, because we are impressed!
civilian you would probably continue with (13 mod 12 = 1) before answering.
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