MATRIXSYNTH spotted this fun jam from Zachary Berry; on a Roland JU-06, D-550, and SDE-1000 with a Yamaha RX5. He's sequencing all of this using the original Auxy app... which you can no longer download.
Messing around with the older version of Auxy (which still has MIDI out functionality) triggering the RX-5 on drums, JU-06 on bass and D-550 for chords. The clap of the RX-5 is routed through the Roland SDE-1000 delay. I wasn't super happy with the end result but it was still neat to see how the iPad can play with hardware so I figured I'd uploaded it anyway.