The Random Sequencer is a circuit that produces clocked randomly changing control voltages. These can also be locked into loops that repeat every 8, 16 or 32 steps.
This is an open hardware project – all the project files (Eagle CAD projects, Gerbers PCB files, a Mouser BOM and Illustrator/PDF front panel designs) are available on this page, covered by a Creative Commons Attribution Share-a-like license, which allows for commercial use.
This is a relatively advanced DIY project, and I’m not able to provide support. I am not selling PCBs, kits or finished modules, but hopefully all the information you’d need to get your own is here.
See the video below for a demo of the Music Thing Random Sequencer in action.