Lolmidi Star Trek + midi. and then Marvin Gaye saves the day. Seriously.
Almost as good as just jamming out to tracks from SuperNES games played by a live Band:
Minibosses Free mp3s from them if you don't know what I'm talking about. You should definitely check out Kid Icarus.
These guys play tracks from your NES childhood on 2 guitars, bass and drums. Some of the guitar arrangements are umm... megabosses!