Theremin

"Influenced by the very reverend trinity of Bach, Bjork and Klaus Nomi, May Roosevelt is an extraordinary thereminist, composer and producer with a sense for good, old-fashioned drama. Her classical arrangements will give you the shivers (or, at the very least, remind you of movies that gave you the shivers), with nods to early industrial or electronic music and a passing resemblance to the god of thunder behind a theremin. Like many people, she got into music via her first Casio synth as a kid. If her knack for otherworldly sounds is anything to go by, that Casio must have been possessed by some very restless and musical ghosts"

This is from May Roosevelt's site where you can find more info and buy her new album Haunted where she deals with 8 Greek dances.

Mass Extermination from May Roosevelt on Vimeo.

And here's a demonstration from the inventor of the magic instrument Leon Theremin.