The Moog theremin is a classic for a good reason. Getting a good sound out of the thing is another issue. Even expert theremin players aren’t perfect. The point is, it’s a really hard instrument to play and most people can’t do more than make space sounds with it. That’s where the theremini comes in. It not only has a pitch correction function, it also let’s you adjust the range, the key, and the scale; there are even effects. It’s relatively cheap as well and I nearly picked one up while I was visiting home recently, but I made the smart choice and decided that I would probably not play it as much as I would like to.
However, at $299, it might have to happen. Get this awesome thing here.