Day 339: Today's Pick — The Theremin

Every musical instrument asks something of your body. Strings want calluses, brass wants an embouchure, drums want your whole skeleton. Today's pick asks for the strangest thing of all: that you touch nothing whatsoever.

The theremin is the instrument you play by not playing it. Two antennas rise from a box — one vertical, one a horizontal loop — and the performer stands before them, hands hovering in empty air. Move a hand nearer the vertical antenna and the pitch climbs; nearer the loop, and the volume falls. That's the entire interface. No keys, no frets, no contact. From the audience it looks like the player is conducting a ghost, and the ghost is singing back in a wavering electric soprano.

An accident of Soviet physics

The theremin was born in a laboratory, not a workshop. Around 1920, a young Russian physicist named Lev Termen — later Westernized to Leon Theremin — was working on radio-frequency measurement devices when he noticed that his own body, moving near the circuitry, changed the frequency of the tone it produced. A human being, it turns out, is a walking capacitor, and Termen realized the interference could be played. The instrument works by heterodyning: two high-frequency oscillators beat against each other, and your hand's position in the electric field detunes one of them, producing an audible difference tone that slides wherever you slide.

The invention became a curiosity of the young Soviet state — Termen famously demonstrated it to Lenin — and then went on tour. By the late 1920s Theremin was in New York, patenting the device, licensing it to RCA for commercial production, and moving through Manhattan society as a celebrity inventor. His later life reads like a spy novel, because parts of it were one: he returned to the Soviet Union in 1938 under murky circumstances, spent years in confinement working in secret laboratories, and developed covert listening technology — including a famous passive bug concealed in a wooden seal presented to the U.S. ambassador in Moscow. He lived long enough to be rediscovered, visiting the West again as an old man before his death in 1993.

The hardest easy instrument

Anyone can make a theremin produce sound; simply walking past one does it. Making it produce music is another matter entirely. There is no physical reference — no fret to find, no key to press — so every note must be located by ear alone in a continuous, invisible gradient, with vibrato and articulation sculpted from pure arm control. It has a fair claim to being one of the hardest instruments to play well.

The proof that it could be played beautifully was Clara Rockmore, a Lithuanian-born violin prodigy whose hand troubles ended her string career and who reinvented herself as the theremin's first great virtuoso. Her recordings of Romantic repertoire — all precise, aching glissandi — remain the instrument's gold standard, and her refinements to technique and to the instrument itself (she worked closely with Theremin, who was, for good measure, in love with her) shaped everything after.

From concert hall to flying saucer

The theremin's second life was in the movies. That quavering, otherworldly wail became Hollywood's shorthand for the uncanny — Miklós Rózsa used it to score psychological unease in Spellbound, and Bernard Herrmann sent it aloft in The Day the Earth Stood Still, welding the sound forever to flying saucers. (The famous wobble in the Beach Boys' "Good Vibrations," a frequent pub-quiz trap, was actually a related touch-controlled instrument, the Electro-Theremin — same family, different species.)

There's one more branch on the family tree worth naming: a young electronics enthusiast named Robert Moog got his start building and selling theremin kits before he built the synthesizers that bear his name. The instrument you play by touching nothing helped fund the instrument that rewired all of popular music.

A century on, you can still buy a theremin, and people still do — some to master it, most to wave at it once, hear the ghost answer, and grin. Both seem like valid forms of worship.