[rikkus]

I found this a while back and have been really enjoying it. http://www.synthesiagame.com

With a laptop that folds flat, you can prop it on the music stand of your piano. Would be best with a touch screen, I think.

[avinashv]

No need for a laptop if you have an iPad. Synthesia has an app. My iPad sits on my music stand connects to my digital piano via USB-MIDI.