I saw a video of this last year; thought it disappeared off the face of the planet.
Concept seems interesting - you seem to play one instrument(?), and runs off some tracker/sampler on steroids format as far as I can tell (meaning the tracks are more midi than audio, allowing the game to sync it up with avatar movement)
However I'm not too sure how complex the game can get from that setup. Not too sure how much lasting value you can get when every song sounds like a Fruityloops experiment gone bad. Dear god the sound. THE SOUND.
YouTube - Band Master Online Official Video 02
Not something I'd want people catching me playing. D: I had high hopes last year because of the nifty teaser music, too.