Have you ever seen an orchestra play? Which instrument is your favorite? Perhaps you like the violins, whose strings vibrate as the violinist moves her bow across them. Maybe you prefer the clarinet, whose reed vibrates as the clarinetist blows air through the mouthpiece. Still others prefer the drums, which blast out their deep tones as the drummer's mallets pound the skins.
Watching an orchestra, you realize that there are many ways a player can interact with an instrument to produce sounds. Sometimes they blow into their instrument, while other instruments need to be plucked or hit.
The theremin, also known as the etherphone, thereminophone, or termenvox, is one of the first electronic musical instruments. It was invented by Russian physicist Lev Sergeevich Termen. The Western version of his name, Léon Theremin, gives the device its name.
He invented the device in 1920 at the outbreak of the Russian civil war, as part of government research into proximity sensors. He eventually brought the device to the United States, where he patented it in 1928.
Unlike other musical instruments, the thereminist plays the theremin without any physical contact. Instead, the thereminist moves his hands near two metal antennas. The antennas sense the relative position of the player's hands and control oscillators for each hand: one for frequency and the other for amplitude.
The antennas produce electric signals that are amplified and sent to a speaker to produce its unique sound. Many people think the sounds produced by the theremin are eerie. Of course, this impression could also be the result of the fact that the theremin's unique sound has often been used in science-fiction movie soundtracks, such as The Day the Earth Stood Still.
Theremin sold the right to manufacture his device to RCA, which began to produce them as early as 1929. However, they have never made a big commercial splash. Today, the theremin remains an instrument seldom heard, especially in popular music.
Perhaps part of the reason the theremin hasn't caught on to a greater extent is that it's a difficult instrument to master. Without touching any part of the instrument, the performer must stand in front of it, moving his hands near the two metal antennas. The distance between the hands and the antennas determines the pitch and volume of the sounds produced.
Basically, the two antennas — one horizontal and one vertical — are surrounded by electromagnetic fields. When hands are moved near the antennas, they create interference, which produces the eerie sounds the theremin is known for. Knowing how to move your hands in ways that produce musical sounds has turned out to be a very difficult skill to master.