Haven’t done this in a long while. I fired up my antique version of MAX MSP and Reaper and used my java based probabilistic sequencer jDelta (code here) to belt out this short improvisation. The sound is a marimba-like tuned percussion designed on the Native Instruments FM8 synthesizer. jDelta allows you to take a short seed sequence (here a repeated cluster chord) and graphically determine the probability of individual notes playing in the sequence, transpositions, velocity or tempo changes in real time using multislider objects. I then improvised a few ornaments over algorithmic variations induced on the seed phrase.
Relevance to posthuman performance practice: JDelta is just a sequencer that allows a certain global control over event probabilities. It assigns played note values to some arrays, then determines the probability of some output related to those values by imposing conditions on a random number output. A smarter program might (for example) use Bayesian statistics or neural networks rather than random numbers to fix the probabilities of an event relative to a given musical context (a little beyond my programming ability at the moment). While the program is not remotely smart, it mediates performance by allowing one to conceive the distribution of events in a graphical way, delegating how the events fall to the machine.