PianoCheetah

It's for playing and practicing a song on piano and drums. Shows notes in a "pianoroll" format that's a little bit fancy.

You practice the piano parts and the background tracks sync to your tempo. Getting a song into your head and fingers is the aim. The real notes of the song can be simplified down to one note per hand max. And your hands can stay in one position. More description / install docs / screenshots on the website.