If you’ve never heard of a Theremin, it was the first electric instrument and according to Wikipedia: The theremin was originally the product of Russian government-sponsored research into proximity sensors. The instrument was invented by a young Russian physicist named Lev Sergeivich Termen (known in the West as Léon Theremin) in October 1920 after the outbreak of the Russian civil war. After positive reviews at Moscow electronics conferences, Theremin demonstrated the device to Bolshevik leader Vladimir Lenin. Lenin was so impressed with the device that he began taking lessons in playing it, commissioned six hundred of the instruments for distribution throughout the Soviet Union, and sent Theremin on a trip around the world to demonstrate the latest Soviet technology and the invention of electronic music. After a lengthy tour of Europe, during which time he demonstrated his invention to packed houses, Theremin found his way to the United States, where he patented his invention in 1928 (US1661058). Subsequently, Theremin granted commercial production rights to RCA.
What is unique about a Theremin is it is played without touching it. You stand in front of the Theremin and move your hands in the proximity of the two antennas. One antenna controls the volume and the other antenna controls the pitch. If you’ve heard Good Vibrations by The Beach Boys, you’ve heard a Theremin. And Jimmy Page made the Theremin famous in the freak out break in Dazed And Confused.