Lev Sergeyevich Termen most well known for creating the ‘Theremin‘ also invented many other electronic instruments based on the heterodyning vacuum tube technology of the day – including the Keyboard Theremin, Theremin Cello, Terpsitone, Rhythmicon and the ‘Electric Harmonium’ or ‘Theremin Harmonium’.
Termen’s Harmonium was an early vacuum tube based polyphonic instrument tuned to accompany and train vocal performances built at the Laboratory of Acoustics and Sound Recording of the Moscow Conservatory from 1926 and continuously developed until the 1960s. The portable desktop instrument had a three octave keyboard with a variable tuning that allowed 1,200 micro-tonal divisions per octave. The volume of the sound could be varied using a special volume roller at the front of the keyboard. The timbre and acoustic envelope could be varied by a “rotary timbre register with 12 different sound characteristics”. The output reached a tuning stability of 3 cents once the machine had been active for fifteen minutes and had a maximum output of 3 watts “increased by connecting a powerful amplification device with additional loudspeakers.” 1 Termen, L. S. (1964) Harmonium for working with choirs, report, Laboratory of Acoustics and Sound Recording of the Moscow Conservatory, TOPIC Z-N, 1964. http://www.theremin.ru/archive/harmonium.htm retrieved 25/11/2023.
“The new Keyboard Theremin which is designed in the form of a piano to produce synthetic music. […] With huge bansk of vacuum tubes, Prof. Theremin conducts experiments in his laboratory which led to a harmonious reproduction of the radio squeals.” (Popular Science, USA, Jun 1932) 2 Radio Squeals Turned Into Music for Entire Orchestra, Popular Science Jun 1932, 51.
Sources:
- 1Termen, L. S. (1964) Harmonium for working with choirs, report, Laboratory of Acoustics and Sound Recording of the Moscow Conservatory, TOPIC Z-N, 1964. http://www.theremin.ru/archive/harmonium.htm retrieved 25/11/2023.
- 2Radio Squeals Turned Into Music for Entire Orchestra, Popular Science Jun 1932, 51.
does anyone know if an example of this instrument survived?
Hi – if anyone knows Andrei does:
http://www.asmir.info/
All the best,
Crab