OK, this is really not for everyone. You have to be a) a fan of the song ‘Crazy’ by Gnarls Barkley and b) appreciate the difficulties in playing a Theremin properly, and in tune.
On second thought, you need to know what a Theremin is! Theremin World will teach you everything you want to know (and don’t want) about what a Theremin is. And that it’s impossible to play it as good as the guy in the clip.
Oh, and don’t worry if you don’t like Theremins – there’s some live MPC playing in it too, just to top it off. Absolutely amazing!