Neutron sound / Magpie modular "Dodeca" versatile MIDI out eurorack module.
Dodeca can be programmed to do pretty much whatever you like with MIDI input, using the standard MIDI library provided withe arduino/teensy
boards and panels will be at magpie modular (add link when live) http://www.magpiemodular.com
additional code by others.
here is a drum brain by Pete Hartman that will use the first 6 notes that are played play as drum outs, each with a trigger out and velocity switched accent. https://github.com/elmegil/Dodeca