The ‘Keyboard Theremin’ Leon Termen, USA, 1930.

Leon Termen's 'Keyboard Theremin' 1932
Leon Termen’s ‘Keyboard Theremin’ 1932


Leon Termen, the creator of one of the first widely used and mass produced electronic instruments the eponymous ‘Theremin’ developed a keyboard version of the instrument during his stay in New York. The Keyboard Theremin used the same heterodyning technique to generate a monophonic tone but this time controlled by a five octave 61 key manual instead of the Theremin’s difficult to master hand gestures. The ex-cellist Termen also added a fingerboard continuous controller so that the player could switch between keyboard and string like playing. The instrument had two foot pedal to shape the sound and add vibrato and a series of organ-like stops to emulate the timbres of conventional instruments such as the organ, Piano, brass, woddwind as well as percussive timpani effects. The amplified output of 100 watts was fed into a bank of six twelve inch speakers.(1)

The 'Theremin Electric Symphony Orchestra' c1932. The Keyboard Theremin is on the right with a Theremin Harmonium on the left and several Theremin Cellos in the centre.
The ‘Theremin Electric Symphony Orchestra’ c1932. The Keyboard Theremin is on the right with a Theremin Harmonium on the left and several Theremin Cellos in the centre.

The Theremin Keyboard was premiered at a concert at the Carnegie Hall in 1932 by the ‘Theremin Electrical Symphony Orchestra’; a ten player ensemble (Termen originally wanted forty musicians) all playing fingerboard and keyboard theremins, each instrument tuned to take the part of an orchestral instrument and performing a ‘conventional’ classical repertoire including J.S.Bach’s ‘Fantasia in G’ and ‘Ave Maria’. Impressed by it’s range and portability, the composer Leopold Stokowski used the Keyboard Theremin at orchestral concerts in Philadelphia, New York and Washington.

'The Theremin Electro Ensemble' later called 'The Electrio' in 1932. (Left)Playing the RCA theremin is Leon Theremin's assistant, Julius Goldberg (with customised "lightning bolt" art deco, brass nickel chrome antennas). (Centre) playing the "Theremin Cello" is the Leonid Bolotine and (Right) Pianist Gleb Yellin is playing a Theremin Keyboard. In 1932, the ensemble could be heard on the radio every Monday afternoon at 2:15 over the Columbia Network, KMBC. (2)
‘The Theremin Electro Ensemble’ later called ‘The Electrio’ in 1932. (Left)Playing the RCA theremin is Leon Theremin’s assistant, Julius Goldberg (with customised “lightning bolt” art deco, brass nickel chrome antennas). (Centre) playing the “Theremin Cello” is the Leonid Bolotine and (Right) Pianist Gleb Yellin is playing a Theremin Keyboard. In 1932, the ensemble could be heard on the radio every Monday afternoon at 2:15 over the Columbia Network, KMBC. (2)


(1)’ Theremin: Ether Music and Espionage’ By Albert Glinsky. p145


‘Music From Electrons’ Radio News. August 1972 P76. Irving J. Saxl. Phd

The ‘Ether Wave Violin’ or ‘Aetherwellengeige’ Erich Zitzmann-Zirini, Germany 1934

The ‘Ether Wave Violin’ or Aetherwellengeige shown here in a 1952 Film

The ‘Aetherwellengeige’ was one of many instruments inspired by Leon Termen’s Theremin using the same heterodyning principle and body capacitance to generate a variable tone from two thryatron vacuum tubes (other instruments were the Sonar (1933) , Neo Violena (1927), Electronde (1927), Emicon (1932) and Croix Sonore (1929) amongst others) . This version was built by the amateur electronic engineer and musician Erich Zitzmann-Zirini in Berlin in 1934 after he had witnessed the Berlin Philharmonic Orchestra using Termen’s Theremin in 1927. Zitzmann-Zirini appeared with his instrument in the 1934 Funkaustellung ‘Orchestra of the Future’

"Sounds from the air from the self-made Ether Wave Violin"
Poster “Sounds from the air from the self-made Ether Wave Violin”

Zitzmann-Zirini used his one-off instrument as the centrepiece of his career in vaudeville, circus, radio, and TV shows, he renamed his instrument the ‘musical Sputnik’ after Gagarin’s space flight in the 1960s.


André Rusch Frankowski ‘Soundscapes’, pp. 23 (1st edition, Berlin 1990)

The ‘Theremin’ or ‘Thereminvox’. Leon (or Lev) Sergeivitch Termen, Russia. 1922

Leon Termen plays the 'Theremin' or 'Thereminvox' . Paris, 1927
Leon Termen plays the ‘Theremin’ or ‘Thereminvox’ . Paris, 1927

The principles of beat frequency or heterodyning oscillators were discovered by chance during the first decades of the twentieth century by radio engineers experimenting with radio vacuum tubes. Heterodyning effect is created by two high radio frequency sound waves of similar but varying frequency combining and creating a lower audible frequency, equal to the difference between the two radio frequencies (approximately 20 Hz to 20,000 Hz). the musical potential of the effect was noted by several engineers and designers including Maurice MartenotNikolay ObukhovArmand Givelet and the Russian Cellist and electronic engineer, Leon (or Lev) Sergeivitch Termen .

One problem with utilising the heterodyning effect (heterodyning is the effect where two high frequency signals are added producing a third audible tone which is the difference of the two high frequencies. This effect was the basis of many vacuum tube based electronic instruments.”) for musical purposes was that as the body came near the vacuum tubes the capacitance of the body caused variations in frequency.


Leon Termen realised that rather than being a problem, body capacitance could be used as a control mechanism for an instrument and finally freeing the performer from the keyboard and fixed intonation. Termen’s first machine, built in the USSR in 1917 was christened the “Theremin” (after himself) or the “Aetherophone” (sound from the ‘ether’) and was the first instrument to exploit the heterodyning principle.

The original Theremin used a foot pedal to control the volume and a switch mechanism to alter the pitch. This prototype evolved into a production model Theremin in 1920, this was a unique design, resembling a gramophone cabinet on 4 legs with a protruding metal antennae and a metal loop. The instrument was played by moving the hands around the metal loop for volume and around the antennae for pitch. The output was a monophonic continuous tone modulated by the performer. The timbre of the instrument was fixed and resembled a violin string sound. The sound was produced directly by the heterodyning combination of two radio-frequency oscillators: one operating at a fixed frequency of 170,000 Hz, the other with a variable frequency between 168,000 and 170,000 Hz. The frequency of the second oscillator being determined by the proximity of the musician’s hand to the pitch antenna. The difference of the fixed and variable radio frequencies results in an audible beat frequency between 0 and 2,000 Hz. The audible sound came from the oscillators, later models adding an amplifier and large triangular loudspeaker. This Theremin model was first shown to the public at the Moscow Industrial Fair in 1920 and was witnessed by Lenin who requested lessons on the instrument. Lenin later commissioned 600 models of the Theremin to be built and toured around the Soviet Union.


Termen left the Soviet Union in 1927 for the United States where he was granted a patent for the Theremin in 1928. The Theremin was marketed and distributed in the USA by RCA during the 1930’s as a DIY kit form or as a finished instrument ( later aficionados of the instrument included Robert Moog who made and sold transistorised Theremins in the 1950s). The heterodyning vacuum tube oscillator became the standard method of producing electronic sound until the advent of the transistor in the 1960’s and was widely used by electronic musical instrument designs of the period.

The Theremin became known in the USA as a home ‘novelty instrument’ and featured in many film soundtracks of the 1940-50’s, it also appeared in several pop records of the 1960’s but never overcame it’s novelty appeal; used for effect rather than as a ‘serious instrument’, most recordings employ the Theremin as a substitute string instrument rather than exploiting the microtonal and pitch characteristics of the instrument. Leon Sergeivitch Termen went on to develop variations on the original Theremin which included the “Terpsitone“, The “Rhythmicon“, the “keyboard Theremin” and the “Electronic Cello”.

Theremin Orchestra, Carnegie Hall. C1930
Theremin Orchestra, Carnegie Hall. C1930


Images of the Theremin

Promotional brochure for the RCA Theremin

NKVD Photograph of Lev Sergeyevich Termen (Russian: Ле́в Серге́евич Терме́н) (27 August [O.S. 15 August] 1896 – 3 November 1993),
NKVD Photograph of Lev Sergeyevich Termen (Russian: Ле́в Серге́евич Терме́н) (27 August [O.S. 15 August] 1896 – 3 November 1993),

Biographical Information: Leon Sergeivitch Termen. 1896 – 1993

The story of Lev Sergeivitch Termen is like some nightmarish John LeCarre novel. Prof. Termen was born in the Russian city of St Petersberg in 1896, he would become one of the most important pioneers in the development of electronic music through his instrument the Thereminvox (commonly referred to as the Theremin). Prof. Termen first invented a prototype Thereminvox in 1920, he worked upon his invention for the next few years, whilst also relocating from Russia to New York. A US patent was granted to Termen for the invention of the Thereminvox in 1928. Termen set up a studio there catering to high society patrons from whom he would extract the moneys he used to continue his experiments. His New York studio apparently was kitted out with a variety of devices, that in the late twenties must have seemed like pure science fiction: a variety of electronic audio devices; electronic lighting shows; an electronic dance platform; even a prototype colour television system.

Lev Termen and Theremin virtuoso Clara Rockmore
Lev Termen and Theremin virtuoso Clara Rockmore

In 1938 Termen was rumoured to have been kidnapped in the New York apartment he shared with his American wife (the black ballet dancer, Iavana Williams) by the NKVD (forerunners of the KGB). Infact he returned to Russia for tax and financial problems in the USA as well as his concerns over the coming war.

“I left New York because at that time the war was coming. The military troops of the fascists were approaching Leningrad, and so on. I asked to be sent to the Soviet Union so as to make myself useful, I asked many times. For a whole year I asked to be sent back. The war had already started, and they didn’t send me, they didn’t send me. Then at last they permitted me. They assigned me to be an assistant to the captain of a large motor ship. So I went home, but they did not take my wife.”


Termen's American born second wife, the dancer Lavinia Willaims
Termen’s American born second wife, the dancer Lavinia Willaims

On his return He was accused of propagating anti-Soviet propaganda by Stalin. Meanwhile reports of his execution were widely circulated in the West. In fact Termen was not executed, but interned in Magadan, a notoriously brutal Siberian labour camp.

 “I was arrested, and I was taken prisoner. Not quite a prisoner, but they put me in a special lab in the Ministry of Internal Affairs. There I worked in this lab just as others worked. [Airplane designer] Andrei Tupolev was imprisoned in such a way too, if you know about that. He was considered to be a prisoner, and I was considered a prisoner too…At one time, on the way to the laboratory, I was sent to a camp, where they did road construction. I was assigned to be supervisor over the prisoners. From there, after eight months on road construction, I was sent with Tupolev to the Aviation Institute. Many important people worked there: [Missile designer] Sergei Korolyov worked there for me.”

Leon Termen interview By Olivia Mattis and Robert Moog 1992

Termen was put to work on top secret projects by the Soviet authorities  (together with Andrei Tupolev, Sergei Korolev, and other well-known scientists and engineers)  which culminated in his invention of the first “bug,” a sophisticated electronic eavesdropping device. Termen supervised the bugging of both the American embassy, (and perhaps, Stalin’s private apartment). For this ground-breaking work he was awarded the Stalin Prize (first Class), Russia very highest honour.

After his rehabilitation Termen took up a teaching position at the Moscow conservatory of music. However he was ejected for continuing his researches in the field of electronic music. Post war Soviet ideology decreed that modern music was pernicious. Termen was reportedly told that electricity should be reserved for the execution of traitors. After this episode Termen took up a technical position, and worked upon non-music related electronics . Ironically his invention the Thereminvox, was becoming vastly influential in America, a development of which he was completely unaware.Before his death in 1993 Prof. Termen made one final visit to America lecturing, and demonstrating his Thereminvox.



“PULLING MUSIC OUT OF THIN AIR: AN INTERVIEW WITH LEON THEREMIN”By Olivia Mattis and Robert Moog. February 1992 issue of Keyboard Magazine.

‘Electronic and Experimental Music: Technology, Music, and Culture’. 2008 by Thom Holmes

‘Sound in Z: Experiments in Sound and Electronic Music in Early 20th Century Russia’. 2013. by Andrey Smirnov.
‘Theremin: Ether Music and Espionage (Music in American Life)’. Feb 2005. Albert Glinsky

The ‘Rhythmicon’ Henry Cowell & Leon Termen. USA, 1930

Henry Cowell and the Rhythmicon
Henry Cowell and the Rhythmicon

In 1916 the American Avant-Garde composer Henry Cowell was working with ideas of controlling cross rhythms and tonal sequences with a keyboard, he wrote several quartet type pieces that used combinations of rhythms and overtones that were not possible to play apart from using some kind of mechanical control- “un-performable by any known human agency and I thought of them as purely fanciful”.(Henry Cowell) In 1930 Cowell introduced his idea to Leon Termen, the inventor of the Theremin, and commissioned him to build him a machine capable of transforming harmonic data into rhythmic data and vice versa.

“My part in its invention was to invent the idea that such a rhythmic instrument was a necessity to further rhythmic development, which has reached a limit more or less, in performance by hand, an needed the application of mechanical aid. The which the instrument was to accomplish and what rhythms it should do and the pitch it should have and the relation between the pitch and rhythms are my ideas. I also conceived that the principle of broken up light playing on a photo-electric cell would be the best means of making it practical. With this idea I went to Theremin who did the rest – he invented the method by which the light would be cut, did the electrical calculations and built the instrument.”

Henry Cowell

“The rhythmic control possible in playing and imparting exactitudes in cross rhythms are bewildering to contemplate and the potentialities of the instrument should be multifarious… Mr. Cowell used his rythmicon to accompany a set of violin movements which he had written for the occasion…. The accompaniment was a strange complexity of rhythmical interweavings and cross currents of a cunning and precision as never before fell on the ears of man and the sound pattern was as uncanny as the motion… The write believes that the pure genius of Henry Cowell has put forward a principle which will strongly influence the face of all future music.”
Homer Henly, May 20, 1932

The eventual machine was christened the “Rythmicon” or “Polyrhythmophone” and was the first electronic rhythm machine. The 17 key polyphonic keyboard produced a single note repeated in periodic rhythm for as long as it was held down, the rhythmic content being generated from rotating disks interrupting light beams that triggered photo-electric cells. The 17th key of the keyboard added an extra beat in the middle of each bar. The transposable keyboard was tuned to an unusual pitch based on the rhythmic speed of the sequences and the basic pitch and tempo could be adjusted by means of levers.Cowell wrote two works for the Rythmicon “Rythmicana” and “Music for Violin and Rythmicon” (a computer simulation of this work was reproduced in 1972). Cowell lost interest in the machine, transferring his interest to ethnic music and the machine was mothballed.

Rhythmicon Discs
Rhythmicon Discs
After Cowell, the machines were used for psychological research and one example (non working) of the machine survives at the Smithsonian Institute. The Rhythmicon was re-discoverd twenty-five years after its creation by the producer Joe Meek (creator of the innovative hit single ‘Telstar’, 1961) apparently discovered abandoned in a New York pawnbrokers. Meek brought it back to his home studio in London where it was used on several recordings. This Rhythmicon was used to provide music and sound effects for various movies in the Fifties and Sixties, including: ‘The Rains of Ranchipur’; ‘Battle Beneath the Earth’; Powell and Pressburgers’ ‘They’re a Weird Mob’; ‘Dr Strangelove’, and the sixties animated TV series ‘Torchy, The Battery Boy’.The Rhythmicon was also rumoured to have been used on several sixties and seventies records, including: ‘Atom Heart Mother’ by Pink Floyd; ‘The Crazy World of Arthur Brown’ by Arthur Brown, and ‘Robot’ by the Tornadoes. Tangerine Dream also used some sequences from the Rhythmicon on their album ‘Rubicon’.
Rhythmicon Discs
Rhythmicon Discs


“Henry Cowell: A record of his activities” Compiled June 1934 by Olive Thompson Cowell.

The ‘Terpsitone’ Leon Termen, USA & Russia,1932

Termen's Terpsitone 1936
Termen’s Terpsitone 1936

The Terpsitone, named after the muse of dance Terpsichorè, was a dance controlled instrument using the same capacitance principles of the Theremin. The Terpsitone was designed built by Leon Termen for his wife who was a dancer. The Terpsitone removed the control antena of the Theremin and replaced it with a large metal sheet hidden under the floor. Movements of the dancers in the area above the sheet caused variations in pitch of the Terpistone’s oscillators due to the capictance of the dancers bodies. This instrument was used for several ‘exotic’ dance, music and light shows throughout the 1930’s.


“During his long and bright life, Leo Sergeyevich Termen made numerous discoveries and inventions. Among the different kind of brilliant inventions was the Terpsitone – which makes it possible for dancers to combine movement of body with music and light. Idea of the Terpsitone occured to L.Termen at the beginning of the 20th century, probably, immediately after the creation of Thereminvox. But as opposed to the Thereminvox where the pitch of tone and loudness depends on the position of the hands of the musician, the Terpsitone frequency and amplitude of sound are determined by a change in the position of entire body of a dancer. The operating principle of the Terpsitone is very similar to the operating principle Thereminvox, based on obtaining audio beat-frequencies, formed by theinteraction of high-frequency fluctuations of two oscillators. One has frequency rigidly fixed, while in the second is variable. In the second oscillator the frequency depends on a change in the distance between the capacitor plates of oscillatory circuit. One of the capacitor plates is an isolated, metallic plate placed on the floor of dancing hall, and second facing the body of the dancer. By moving through the space the dancer affects a change in the capacity of oscillatory circuit and, correspondingly, a change in the difference audio frequency. This signal is amplified and sent to the loudspeaker. Thus the motions of the dancer is converted into sound, which change synchronously with a change in the position of body.

The possibility of adding automated colour is an additional special feature of the invention. The “visual sound display” is a panel with  lamps, painted in different colours where the lamps light up to the motion of the dancer, moreover lamps with the specific colour corresponds to each note. However, this is ensured partially mechanically.

The Terpsitone in the acoustic laboratory, Moscow, 1966 consists of:

1) the electronic-music block, which works on the principle of Thereminvox with heterodyning high frequencies, with the device for vibrato and by a change in the loudness of sounding loudspeaker

2) An  electrical capacitance dancing platform with the size of 2 X of 1,8 X of 0.2 meters with that placed under it along entire its length and width by the electrode, connected through the resonance involving system with one of the high-frequency generators of musical block;

3) A dynamic loud-speaker with control of intensity and timbre. A Range-tool for the performance of melody by the motions of arms, head and legs of the dancer who stands on the platform – 2 octaves. More low-pitched sounds correspond to the locked position of hands and housing of that dancing, high to a maximally opened position, with the large external overall sizes. This experimental device adapts for training the executors of this new form of choreographic- musical skill. Are developed also the electrical circuits of the additional devices:

3.1) movement of executor forward gives audio gain, and its presence in the background ceases sound by means of the electrical capacitance influence on the electrode, fastened on the rear wall of dancing platform

3.2) the invariability of the pitch of tone with the displacement of that dancing and the appearance of that corresponding to the position of the executor of the new height of sounding with the cessations of motion.

Executors: Heads by the laboratory of acoustics and sound recording – Yurchenko A.D, the supervisor of sector – Termen L.CH., engineer – Rudakov YE.A., engineer – Matveyev V.N., technician

Termen’s “Terpsitone” by gimazutdinov K.N., Kazan, NII – SCIENTIFIC RESEARCH INSTITUTE “Prometheus”, 1996