The Theremin, the instrument known for the ghostly whoops and wavers on recordings by Led Zeppelin and the Beach Boys, has never been particularly mainstream but its fans are preparing to celebrate 100 years of hands-free noise.

The world’s first manufactured electronic musical instrument, the Theremin works by having the player disrupt an invisible electromagnetic field with their hands. Their movement affects the instruments pitch.

“As much as it’s like a string instrument, it’s also like a human voice,” said Montreal’s only Theremin teacher Aleks Schurmer. “I think it’s the instrument that approaches the human voice the most, because it can play every crack in between all the notes.”

The Theremin was invented by the Russian physicist and engineer whose name it bears, Leon Theremin in 1920. Theremin first came up with the idea for the instrument while working on a proximity sensor. After moving to America, electronics company RCA began manufacturing it. In 1938, Theremin mysteriously returned to Russia before the instrument could gain mainstream appeal, with some claiming he had been kidnapped by Soviet agents or had been a spy himself.

“He spent a long time at a gulag for scientists, where scientists were forced to work for the state,” said music writer Sean Michaels. “While he was there, he developed one of the most notorious bugs of the Cold War, which was used to spy on the American ambassador in Moscow.”

Today, players are few and far between, but those who play swear by it.

“If I give you a violin or a trumpet there’s a lot of technical questions involved,” said Schurmer. “I need to know which button to press, which key to pull, how does it work? But the Theremin sort of removes all those elements because it’s just literally imaginary. It’s just something in the air.”