I've bought recently a Midi usb keyboard, and wanted to get it working on Haiku. So, as usb_midi driver is not included in night builds I compiled my own. After testing with R29014, R29065 and R29080, It worked (after a lot of plugs and unplugs). May I post a ticket or it's just to early for that?
I've been looking at usb_midi source, but can not guess whenever the driver is completed or not.