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Theremin electronic instrument

Classic Projects: Theremin electronic instrument

Find out about the Theremin - a musical instrument that can be played without being touched.

AstheTheremin is one of the simplest of electronic musical instruments, there has never been a consensus over what it should look like.

Basically, it has two antennas (one for pitch and the other for volume) connected to a box of simple circuitry. The only real consideration when building one is that the player should be able to get their hands within the pitch field.
Early models looked like classic pieces of Art Deco furniture, while the more modern versions resemble straightforward boxes of electronic gadgetry. There is no need for physical contact to play one, which is unique in the world of musical instruments.

The debate will go on, but most commentators think that the brainchild of Soviet inventor Lev Termen (who later became Leon Theremin) is one of the earliest mass-produced electronic musical instruments.

Invented in 1919 and first demonstrated in the United States in the 1920s, the theremin is perhaps best known as the device that provides spooky sound effects for classic 1950s sci-fi movies (such as ‘The Day the Earth Stood Still’) and 1970s psychedelic rock. Despite what the public routinely thinks, it doesn’t appear on the Beach Boys’ Good Vibrations, the Star Trek theme or the signature tune for Dr Who. However it does have a canon of early 20th century classical as well as avant-garde music. It was also put to good use by the Rolling Stones, Led Zeppelin and, in more recent times, the Pixies.

The instrument works in a remarkably simple way, based on the principles of heterodyning and capacitance. Two antennas control pitch and volume: the player’s right hand finds the notes while the left changes articulation and dynamics. Although resembling aerials, the antennas are not transmitting or receiving radio signals, but are in fact acting as capacitor plates. The audio generated is the result of the combination of a fixed-frequency oscillator in the theremin device itself and a variable frequency created by the movement of the hands. These movements have been refined over the years to the point where a highly skilled thereminist like Carolina Eyck is able to teach standard techniques for playing the instrument accurately.

As with many musical instruments, the basics are elementary. Yet its execution is fiendishly difficult if you want to do anything other than create convincing Halloween sound effects. Because of the simplicity of its design, it has passed into myth that theremins are easy to build. While it is true that you can buy mail order kits and that it was a frequent cover star of 1950s home electronics magazines, it’s better left to the experts.

One such expert was engineer Robert Moog, who took hold of the theremin’s design principles and applied them to producing an instrument using a piano keyboard interface. With this innovation, the blueprint for the modern synthesiser - the Minimoog Model D - was born.

As for the inventor, it was a life shrouded in mystery. After the outbreak of the Russian Civil War, he fled to the United States, where he was granted a patent in 1928 and went on to produce the instrument through the company RCA Thereminvox.

Even though the device fascinated audiences, commercial success did not follow. About 500 of the original theremins were manufactured and only half of them are known to still exist.

By the outbreak of the Second World War, Theremin had disappeared - allegedly, kidnapped by NKVD, the precursor to the KGB, to serve in Soviet labour camps - only to reappear in the US in 1991.

Next month: Rubik’s Cube

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