In the 1920s and '30s, Russian emigre Leonard Theremin -- the inventor of the world's first electronic musical instrument -- had it all. His self-named theremins were in high demand from filmmakers and musicians around the globe; he was married to a beautiful American dancer; he lived among New York's social elite. And then, in 1938, he mysteriously vanished, not to be seen again for over 50 years.
