By Bad Seed
Harry (aka Harry The Piano) plays the Harry Potter Piano Theme Tune in (almost) every style known to man. This was not rehearsed and the cameraman barked out ideas for the arrangement on the fly while Harry improvised around the Harry Potter theme tune. There's a lot of piano notes, and you'd never be able to play this from the sheet music as it was improvised - see if you can hear the other song styles that are hidden in the deluge!
More at http://www.harrythepiano.com