MIDI-Jammer turns your DS into a wireless MIDI Controller. It lets you “draw” musical ideas and shapes in a manner that is both easy to pickup for a non-musician and also consistent/coherent enough that those who are trained musicians can have a high-degree of MIDI control through the interface.

Discussion and release thread: http://forum.gbadev.org/viewtopic.php?t=15173

http://www.andrewbuch.com/prog.php