This could be worth a read:
http://www.gimp.org/unix/howtos/gimp-midi.html
It's something I'm interested in doing myself, but haven't had the
time to try it yet - I'd be interested in your thoughts on GIMP & MIDI.
Gavin.
I've not noticed this before but it interested me. I've done some
experimenting, only to find that the controller channels don't work
properly. I've filed a bug report with the GIMP (
http://bugzilla.gnome.org/show_bug.cgi?id=537960 ) and a patch which has
been accepted so if you do want to try it, you might want to have quick
look at the bug report to see what might happen.
Simon Fielding