Magic Piano 1.0
the author of this app says:
Play timeless pieces on spiral and circular keyboards, or follow beams of light mastery requires only imagination. Play alone, or travel through a warp hole and play Piano Roulette with other performers across the world. Designed exclusively for the iPad by Smule, creators of Ocarina, Leaf Trombone, and I Am T-Pain.
Compatible with iPad. Requires iPhone OS 3.2 or later.