To answer the question in the headline of this article, the short answer is: yes. Jim Parsons actually taught himself how to play the theremin for "The Big Bang Theory." In the episode "The Bus Pants Utilization" (January 6, 2011), the lead characters gather together to invent an app that lets users solve differential equations. Such an app, they figure, is specialized enough that no one else has published one yet, and they begin to have fantasies about potential wealth and fame. Sheldon (Jim Parsons, giving a career-altering turn), however, begins to fantasize that their roommate Penny (Kaley Cuoco) might be angling to steal their idea, even though she clearly wants nothing to do with it. Sheldon also becomes preoccupied with their team's command structure and who the leader might be. He becomes caty, cruel, and vindictive, making fun of his teammates to assert his leadership over them. Advertisement Sheldon is eventually, understandably, kicked off the team. As revenge, he extracts his theremin while his friends are having a meeting, and plays it as loudly as possible. This will eventually get Sheldon kicked out of the apartment as well. He will end up playing "Nobody Knows the Trouble I've Seen" in the hallway, trying to sing along to his own theremin playing. Penny will have to teach Sheldon how to apologize before he will be let back in. Yes, that was a real theremin, and yes, Parsons was actually playing it. He admitted in a Paleyfest interview (reported on by The Hollywood Reporter) that he wasn't very good at playing the theremin — he said that his inabilities brought him to tears — but he was actually playing it. Advertisement