This shows the archetypal 70s/80s sample/hold controlling a filter cutoff with high resonance. The Moselle Hold module holds its output value steady until its internal timer goes off, at which point it re-samples the input to get a new output value. The default input is simply the function Random (), which gives you a random number.
In this patch, the knob on the MIDI controller is used to fade between three Holds, running at 2Hz, 4Hz, and 8Hz.
Note the sound is recorded directly from Moselle: no hardware or external processing was used.