How does a theremin work?
When you ask someone what instrument they play, statistically speaking, you’re very likely to get one of the classics that everyone has heard of and can speak with some degree of knowledge on. We all know what guitars, pianos and drums look and sound like and how they’re played. In the majority of popular music, these are the most commonly featured instruments.
Sometimes, you might get a slightly more unusual response. For example, there are probably significantly fewer harp players out in the wild that you can quiz on their instrument, and there are probably even fewer trombone players that you encounter at your average gig. But you’ve still got a reasonable idea of what they look like, the sounds they make, and how they’re played.
However, every once in a while, you’ll get a response from someone whose instrument of choice is so unusual that you simply have to ask, “What the fuck is that?” Their weird and wonderful sounds are almost certainly things you’d recognise having heard before, but what they look like and the science behind how the player can achieve said sounds might be a total mystery. Among the most perplexing musical instruments ever devised is the theremin, which you may know by name or sound but be completely flummoxed by how it can produce its ethereal tones.
The sound it produces is akin to a synthetic violin or a higher-register vocal, but unlike other early electronic instruments, the synthesis of its sound isn’t through a tactile keyboard or any dials or buttons. In fact, it works without any human contact whatsoever. So how do you play it?
How does a theremin actually work?
The theremin works through the power of electromagnetic interference and is controlled with two separate antennae—one for adjusting the pitch and one for adjusting the volume at which it is played. The slightest movement from either of the player’s hands can alter these two features dramatically, so a large amount of delicate control is required to get the instrument to function properly.
Because the human body is an electrical conductor, the radio frequencies can pass through the player with one of the antennae fixed at a particular frequency and the other kept variable. The instrument then measures the difference between the two frequencies being transmitted to create its unique pitched sound.
The inventor, Leon Theremin, was a Russian scientist who conducted experiments with high-frequency oscillators that could measure electric force. While conducting his experiments, he discovered that it was possible to change the pitch of the signal by altering how close to or far away from the receiver he was standing. From there, he began working on a way to harness the potential of the device to create a functional musical instrument.
The theremin’s creation was one of the first mass-produced electronic instruments and became available for people to purchase following its patent in 1928. Since then, its use in electronic composition has become increasingly popular, with players such as Clara Rockmore using it in more classical environments. In more contemporary settings, you can hear it in the works of Frank Zappa and The Beach Boys, with ‘Good Vibrations’ boasting one of the most well-known examples of theremin use in popular music.
While this was the only musical device Theremin ever devised and created, he also came up with the concept of ‘The Thing’, which was a covert listening device used by intelligence services to intercept and transmit signals. However, his eponymous device remains his greatest invention and one of the most innovative instruments ever created.
