Thank you both! Ill work on getting stuff for the arduinoboy.

And the price of the Rock Band Keytar is exactly what made me want to do this, A cheap MIDI keyboard would be great.

you don't need to build the midi stuff inside the gameboy itself. it's cool that people do it, but you can build an arduinoboy that's external much more easily. there's a great tutorial on building arduinoboys on instructables.com

also, search this board and the 8bc board because someone was just selling arduinoboy kits that included everything you'd need to build your own.

Arduinoboy adds midi to the gameboy and mGB lets you access all the gameboy channels on different midi channels. You can also set mGB to play PU1 PU2 and Wav in a polyphonic mode on 1 midi channel so you get 3 note polyphony.

I've actually played around with the Rockband keytar and it works pretty great as a midi controller for the price.

I was curious today, and i was looking up the Rock Band 3 keyboard peripheral, and i started wondering, since there's the MIDI port on the keyboard, wouldn't it be possible to connect they keyboard through MIDI cables to a Gameboy with a MIDI port added to it (like NeX has done)

And if this is possible, are there any tutorials or instructions on how to add the MIDI port to the Gameboy?