One curious fact about the theremin that I forgot to mention in my previous post, is that unlike conventional instruments, EVERYBODY IS AN EXPERT.
I always advise people never to take advice on playing the theremin from anyone they have not heard play, or from anyone whose playing they have heard but did not particularly enjoy.
With traditional instruments there are international standards of performance and established, time-honored techniques for playing. The theremin has not been around long enough to have anything that could be called a "tradition" associated with it, and between 1932 (when RCA ceased manufacture of the instrument) and the very first theremins of the late Bob Moog, there was a hiatus in production of more than 20 years.
All you have to do in order to call yourself a "thereminist" is own a theremin. No one who simply owns a violin would dare call themselves a violinist, but with the theremin you can get away with anything!
The tragedy of the theremin is that the vast majority of players are self-taught. They are not only both teacher and student, they are also their own final examiners and the adjudicators of their success.
I can't tell you how many people whose playing is REEEEEEELY bad, have told me over the years how proud they are of their success at mastering the instrument! And the one thing they have in common is their fervent desire to show as many people as possible how to follow in their footsteps!
"I followed in the delicate footsteps of Edna St. Vincent Millay in my dirty sneakers". Dorothy Parker ☺