[sdiy] USB to MIDI example projects?

[johnspeth at yahoo.com]

Hi everybody-

I'm starting to experiment with a DIY project that will have a tone generator of some sort driven by a USB-MIDI interface (specifically the USB Device Class for MIDI Devices).  Can anyone point me to a project that includes C source code on a microcontroller showing an implementation of a USB-MIDI interface?  What I could find on google wasn't very complete or instructive.

Thanks for helping me, 
John Speth.