I don't know how accurate the information is on this YouTube video, but it looks like a very old video clip.
http://www.youtube.com/watch?v=LBuCzWk7SuQ&mode=related&search=theremin
Any of our German readers have an idea who this might be?
http://www.youtube.com/watch?v=LBuCzWk7SuQ&mode=related&search=theremin
Any of our German readers have an idea who this might be?