So far we've had a few song suggestions. We've had suggestions to play:
-Clanker's Cavern (Banjo and Kazooie)
-Redo Traverse Town (but with more instrumentation)
-Ein suggested Battle on Requiem (Yggdra Union)
-Skullkid suggested The Promised Land (Advent Children)
Plus we've had a whole bunch of suggestions on the irc but nothing has panned out yet.
I want to suggest Casino Night Zone from Sonic 2 but as an improv jazz piece. The way it would work (this would take a bit of creative arranging) would be that the entire band plays the main theme of the song as an intro, then there would be a section for improvisation by whoever wants to, followed by the entire band playing again at the end. Piano, drums, and bass would play during the improv just basically comping (the sheet music would indicate the chord progression). This would probably just involve the piano playing specific chords and the improver would play above them.
Either that or we do Hilltop Zone. A lot of the sonic 2 and 3 songs have piano. Plus dat wailing sax.
Just a couple of suggestions on my part. We are still open to more suggestions by everyone (cough cough Raz). Remember we ideally want a song that involves as many instruments as possible and hopefully piano.