I gave a talk on Theremin and his many inventions a couple of years ago! http://idlewords.com/talks/our_comrade_the_electron.htm

I highly recommend the documentary called "Theremin: An Electronic Oddyssey" http://www.imdb.com/title/tt0108323/

And "Ether, Music & Espionage" is an engaging biography: https://www.amazon.com/Theremin-ETHER-MUSIC-ESPIONAGE-Americ...

My favorite factoid about him is that late in life, Theremin became convinced that the secret to immortality lay in "young blood". Certain billionaires seem to be testing his theory today.