C. Chris Peters on the Etherwave Theremin
The theremin is one of the earliest totally electronic musical instruments ever made. Invented around 1920 by a young Russian musician / scientist named Leon Theremin, it predates the invention of the electric guitar and electric organ.
The most unique thing about the theremin is that it does not require the player to make any physical contact with it while performing. The thereminist’s body actually becomes part of the electrical circuit that controls its pitch and loudness.
The theremin is a wooden box with two antennae coming out from its sides. These antennae provide simultaneous and continuous control over the pitch and loudness of musical tones. The vertically oriented antenna controls the theremin’s pitch and the horizontally oriented looped antenna controls the theremin’s volume.
The most challenging aspect for performers about playing the theremin is that it has no physical reference such as a fret or key to define musical notes. The thereminist must be able to imagine what is going to be played beforehand, and as closely as possible, match the note to some physical proximity in space.
The theremin is very sensitive to body movement. Any change in the performer’s position to the instrument will affect its pitch. Performers learn very quickly to stand absolutely still and only move what is necessary in order to stay in tune.
The closer you put your hand to the vertical antenna, the higher in pitch the tone gets. Moving your hand away causes the pitch to drop. The closer you put your hand to the horizontal antenna the quieter the tone gets. Moving your hand away makes the tone louder until it reaches the point of the full volume.
The two antennae broadcast small energy fields that are sensitive to interference. As energy absorbing objects (or human body parts) enter these energy fields; they progressively influence the behavior of the fields which intern affects the behavior of the theremin’s circuitry. The body acts in a similar way a capacitor does when tuning a radio to a particular station.
The theremin’s pitch circuitry is made up of two oscillators; one is operating at a fixed frequency, the other at variable frequencies. Tones result from the frequency differences of both oscillators sounding together. Hand movements effect the tuning of the variable oscillator.
The volume circuitry squelches or turns off the tone. The closer your hand is to the volume antenna the more it interference it causes. Eventually this interference will be great enough to cause the circuit to prevent tones from sounding altogether.
The theremin was very popular with composers who wrote music scores for early science fiction and horror films. Some famous movies that feature theremin sounds are “The Lost Weekend”, “The Day the Earth Stood Still”, “It Came from Outer Space”, “Rocket Ship X-M”, “The Thing” and the more recent “Ed Wood”.
I frequently demonstrate and perform with my theremin in venues such as classrooms, museums, street fairs, and music festivals. I also play theremin live and provide original music using laptop computer applications on WUSB, Stony Brook’s radio station for the Free Software Roundtable program.
© C. Chris Peters 2010