Recipe:
One IKM UNO flat-panel keybed synth set to 4 octaves, arp and latch mode active
One old skool synth or rack unit with drums mapped across it's keys, Alesis, Proteus, Yamaha XG etc
Reaper daw hosting some vsti drum plugin with midi-out... I used HG Fortune's Drumburst plugin in this case
Connect Drumburst or other fav to a Red Zeppelin LV2i drum plugin
Start Hydrogen playing a separate simple solid beat
Start Drumburst playing itself, and the Red Zeppelin kit
Connect the UNO to the oldskool synth by midi cable, pick a mapped kit, and tap and/or gliss...
keep testing til you find a keeper pattern, and choose Reaper's 'save live output to disk' option.
Now in the UNO arp, latch mode keeping the beat going, modify it's playback direction a few times, and use the random option for a bit.
When finished recording, fire up your audio editor, trim, copy, cut, and paste as desired. BOOMMMMmmmWhole Lotta Beats
Use Audacity to play it at different tempos, and re-record the finished track using Timemachine or your fav utility.
With a multi-input interface, the UNO's analog synth audio output is still available for more experiments.
A used UNO and old-skool synth should run around $300