Principle
Chance and selection
JCself determines values in an iterative process. Every choice changes the probability of the next one.
Try it
This small browser version shows how JCself calculates. Blue is the current value, red the most frequent so far, green the seed frequency. The red line at the top shows the distance between current and most frequent value, from which JCself derives duration, loudness and stereo position.
What JCself produces
JCself writes either a MIDI file or an orchestra and score file for the sound synthesis program Csound. Both can be processed further.
How JCself decides
In each step JCself chooses a value. The more often a value has already been calculated, the more likely it is to be chosen again. The probability distribution therefore forms only while the program runs. Through this self-organisation, synergetic structures emerge.
The composer only sets the conditions. They concern the possible properties of the tones and the probability calculation. After that, JCself composes on its own.
From value to tone
Every calculated value is a pitch in hertz. JCself derives all other properties of the tone from the distance between the current value and the most frequent value so far. The closer the current value is to the most frequent one,
- the shorter and louder the tone,
- the more central its stereo position (given a pair of speakers),
- the more voices surround it,
- the more consonant any added interval (see Counterpoint).
Direction matters for panning as well: a value below the most frequent one sounds on the left, a value above it on the right.
The table
While JCself calculates, it shows a two- or three-dimensional table. It spans the frequency range between the minimum and maximum frequency set by the composer. Each column stands for one frequency or a range of frequencies.
- Blue arrow
- the current value. It leaves an entry in its column.
- Green arrow
- the seed frequency the composition starts from.
- Black arrow
- the most frequent value so far.
The table is normalised: the most frequent value always spans its full height. The live version on the home page shows this table in the browser, with the most frequent value highlighted in white.
Additional material
Melodies, cascades, loops and tempo changes are triggered by a further stochastic method, described under Machine.