Envisioned a century ago as the music-maker that would be found in every home, today it's basically a cult instrument.
Sheldon plays the theremin on The Big Bang Theory. So does Millhouse on The Simpsons. And a cat plays one on the Internet, in a YouTube video that's been viewed more than 500,000 times.
On Wednesday, for a moment, Philadelphia will stand at the center of the theremin universe - through a lively musical-literary mash-up that features a local virtuoso and the author of a new novel about the instrument's inventor, a Russian scientist and spy named Lev Sergeyevich Termen.
It's pretty weird. Which suits Eric Bresler.
"It's right up our alley," said the director-curator of the Philadelphia Mausoleum of Contemporary Art, set in a former tombstone showroom on 12th Street near Ridge Avenue.
Audience members will get a chance to play a theremin at the event.
The instrument looks something like a radio, with antennas that control pitch and volume. Because the theremin is played without touch, it offers the musician no visual reference. And no tactical memory - air can't be felt like a fretboard. More, the instrument is microtonal. That is, it contains a wide range of sound between, say, an E and an F. On a piano, by comparison, one note sits beside the next, full and complete.
"Every warm-blooded human being can provoke a sound from a theremin," said Sean Michaels. But only a few can provoke music.
He should know. Michaels is the author of Us Conductors, an unusual novel that imagines the life of the theremin's inventor.
The true story is strange enough.
Termen invented one of the world's strangest instruments in 1919, and in the 1920s he traveled to the United States to promote his device.
Taking the name Leon Theremin, he met with almost instant acclaim, setting up a Theremin Center in Manhattan, signing a production contract with RCA, and dining with new pals Charles Chaplin and Albert Einstein.
In 1928, Theremin performed with the New York Philharmonic. Four years later, he conducted the first all-electronic orchestra - sparking dire predictions that his machine would mean the end of traditional orchestras.
Among his students was the Russian-born violin prodigy Clara Rockmore, who took up the theremin when problems with her hands left her unable to finger her instrument.
"Under her control," wrote the website Theremin World, "the theremin sounded like a blend of the cello, violin and human voice."
She became the world's best player - and the object of her teacher's fascination. His unconsummated love for Rockmore became legend in theremin circles.
In the 1930s, Theremin took as his second wife a prime ballerina from Philadelphia, Lavina Williams. Because Williams was black, their union was considered scandalous.
Their life together was short.
In 1938 he returned to the Soviet Union - abducted by Russian agents, fleeing the U.S. tax man, or merely unbearably homesick, depending upon the telling.
Convicted of spreading anti-Soviet propaganda, he was locked up in a Siberian prison. For years he was thought to be dead. In fact, Theremin had been quietly assigned to a secret prison lab, where he labored for the intelligence services.
Among his inventions was a listening device known as "the thing," today better known as a bug. Theremin's device was embedded in a Great Seal of the United States presented as a gift to the Americans in 1945. It allowed the Soviets to spy on the U.S. ambassador for years.
Leon Theremin was freed in the late 1940s, continued working for the KGB into the 1960s, and then moved to a Moscow conservatory where he built theremins and other electronic instruments. He died in Moscow in 1993 at age 97.
His instrument has been ignored by most and adored by a special few. It inspired Robert Moog, who built theremins before he created the synthesizer that bears his name. The guitarist Jimmy Page of Led Zeppelin played a theremin on some songs. So did the alternative rock band Pixies and the Jon Spencer Blues Explosion.
Michaels, a Montreal music critic, began investigating Theremin at the suggestion of a friend, fascinated by a true story that seemed so outrageous as to be a lie, but one that contained lies of such heft they seemed surely to be true.
In writing about the inventor and his student, the theremin becomes a metaphor for longing - an invisible, hard-to-control force.
"You mention the instrument to someone," Michaels said, "and there are two responses. One is a completely blank look. The other is, their eyes light up and they have so much enthusiasm."
Mano Divina stands firmly among the latter.
He's performed and lectured on the theremin across the world, the founder and leader of the Divine Hand Ensemble, which plays classical compositions. He'll perform Wednesday.
Divina grew up playing guitar, bass, and drums, but his life changed forever when he first saw a theremin played in 1997.
"I went through a very unusual range of emotions," Divina said. "First was, what is this B.S.? The next was, something's going on here that I don't understand, and I do believe he's creating some kind of music with his hands in the air. By the time he was finished, I thought it was the most amazing thing I ever saw."
Instantly seeing the instrument as a vehicle for opera, Divina had to have one.
"Now it's all I do," he said. "Imagine an opera singer who never had a voice, and suddenly got a voice one day. . . . My group's job is to show it, tell it, and most importantly to entertain you with it."
See a video of Leon Theremin playing his own instrument at www.inquirer.com/