As part of a university assignment, I wrote a Purr Data patch using random pitched, picked from the octatonic scale, and random rhythms. This patch has a list of pitches and rhythms. The slider in the video indicates the range in which the list gets read. So the higher the value, the higher the amount of pitches and rhythms you the patch can pick from. Thus the slider controls the amount of randomness in the composition.

Generative Piano Etude from Maya Composer on Vimeo.