Electronic Interfaces for Musical Expression | Part 2 | 1915-1950.

anant rohmetra
1 day ago
6 min read

In 1907, a year after the Telharmonium's first public demonstration, Cahill began a brief collaboration with inventor and "Father of the Radio" ( Title of his autobiography ) Lee De Forest. In January of that same year, he had received a patent for what would become his most famous and influential invention, the audion triode vacuum tube.¹ The immediate effect of De Forest’s triode valve was in the emerging radio technology. De Forest also discovered that the valve was capable of creating audio frequencies using the heterodyning also called beat frequency. Combining two high frequency signals to create a composite lower frequency in the audible range.

Let's suppose a radio station transmits at a carrier frequency of 1,000,000 Hz (1 MHz). The receiver uses a local oscillator generating a frequency of about 1,000,500 Hz. These two radio frequencies are mixed (heterodyned) in the receiver's mixer stage.

The mixing creates two new frequencies:

The sum: 1,000,000 + 1,000,500 = 2,000,500 Hz (too high to be audible)
The difference: 1,000,500 − 1,000,000 = 500 Hz (within audible range)

Image Courtesy 120 Years of Electronic Music¹

Lee De Forest’s Audition Piano(1915) was the first Vacuum Tube Instrument and marked the beginning of an era. Piano was a simple keyboard instrument but was the first to use beat frequency(heterodyning) oscillator systems and body capacitance to control pitch and timbre. De Forest describes the instrument as, “ the pitch of the notes is very easily regulated by changing the capacity or the the inductance in the circuits which can be easily effected by a sliding contact or simply by turning the knob of a condenser. In fact, the pitch of the notes can be changed by merely putting the finger on certain parts of the circuits. In this way very weird and beautiful effects can easily be obtained.”

Image Courtesy Efemello²

The Theremin (1917) used the principles of beat frequency and heterodyning oscillators were further used by Lev Sergeivitch Termen to make “The Theremin”. One problem with utilising the heterodyning effect for musical purpose is that as soon as the body came near the vacuum tubes there was a variation in capacitance leading to a change in pitch. Teremin rather than seeing it as a problem used body capacitance to make the first non-contact & continuous pitch instrument. The original Theremin in 1917 used a foot pedal to control the amplitude. Theremin in 1920 was a unique design with 4 legs with a metal antenna and a metal loop. The instrument was played by moving hands around the metal antenna and the metal loop to control pitch and amplitude respectively.

At the Moscow industrial Fair (1920), Lenin, the first head of government of Soviet Russia saw the instrument and requested private lessons. Later he commissioned 600 models of the Theremin to be built and toured around the Soviet. For the first time ever, so many models were made for an electronic instrument. Theremin moved to New York and was granted a patent for the invention of Thereminvox(1928). In 1938 Theremin was kidnapped by The People's Commissariat for Internal Affairs, Russia( NKVD). He was transported to Russia and accused of propagating anti-Soviet propaganda by Stalin.

Theremin was put on a top-secret project culminating in his invention of the first ”bug”, a sophisticated electronic eavesdropping device.

Theremin was widely used in film sound tracks and famously in “Good Vibrations" by Beach Boys but it never overcame its novelty and was always used for effects rather than a serious instrument(120 Years of electronic Music).

The 1920s was an era of experimentation and the avant-garde; composers and inventors were eager to explore new sound possibilities beyond conventional instruments, fueled by movements like futurism that embraced machinery and electronic noise as artistic expressions. There was also an upsurge in popular music and Jazz music. Phonograph records, often called 78s because of their rotation speed (around 78 RPM), were widely sold and fueled music consumption during that era

Image Courtesy 120 Years of Electronic Music ³

The Sphärophon /The Electrophon ( 1924) by Jörg Mager made in Germany was one of the earliest electronic musical instruments designed to explore microtonality and non-traditional tuning systems.

It featured a sliding keyboard or lever-based interface that allowed the performer to smoothly glide between pitches—like a Theremin, but with tactile control.

Frederick Prieberg said, “Marger produced today an organ with many registers on which four voices playing is possible. So far there is only one difficulty; that is, that each voice must have its own keyboard, thus the four voice movements must be played on three manuals and the pedal.” This was an early form of polyphony in musical instruments.

Image Courtesy 120 Years of Electronic Music ⁴

The Cellulophone(1927 )was invented by French engineer Pieerre Toulon which was an electro-optical tone generator with a 2 eight octave keyboard and foot pedal. The sound was generated by rotating discs in which a ring of equidistant slits were cut(54 slits for the lowest tones), different shape marks generated different timbres. The increase in sophistication of circuits marked the decline of light based synthesis after the 1940s except Daphne Oram among a handful of others who used similar systems not only to synthesise sounds but to sequence sounds.

Pierre proposed a related technique of speech synthesis using fragments of optical film mounted on a rotating drum.

The Clavier a Lampes (1927) was made by Armand Givelet at the radio laboratory at Eiffel Tower. The instrument used a vacuum tube monophonic oscillator. Givelet came up with the concept of ‘silent recording’ that is not using a microphone to record the instrument but to feed the output signal directly into a radio transmitter or sound recorder as the microphones back then were very low quality.

He further went on to make ‘Orgue des Ondes’ or ‘Wave Organ’ which was supposed to be a cheap replacement for the organ which was widely used to play popular music of the time. It again used to wire to transit audio into amps or radio transmitters. This idea was further used to make guitars louder AKA the electric guitar.

The organ had as many as 1000 tubes in total for the amplifier and oscillator. It gave it a pitch range of 70 notes and more than 10 different timbres to play with.

The Sonar(1930), among many other instruments made by Termin, the Sonar was said to have been able to reproduce simple speech phrases such as “mama” “papa” as well as conventional instrument sounds.

Image Courtesy 120 Years of Electronic Music ⁵

The Singing Keyboard(1936) made by f.Samis was aprecursor of the modern sampler, the instrument played electro-optical recordings of audio waves on strips of 35mm film which were triggered using a keyboard. It used similar technology of triggered and pitched magnetic tape.

Image Courtesy 120 Years of Electronic Music ⁶

The Vocoder ( Voice Operated Recorder in 1939 by Homer Dudly who was a research physicist at Bell Labs who made a device consisting of an analyzer and an artificial voice. The analyser detected the energy level of a series of narrow frequency bands. The synthesizer reversed the process by scanning the data from the analyser and supplying the result to a feedback network of analytical filters energised by a noise generator.

No human vocal cords entered into the procedure and simply by pressing keys various phrases could be produced like “She saw me”, “Ha ha ha”, “Mary has a little lamb”, etc. It also had a vibrato to make a singing voice or to depict an older person’s voice.

Image Courtesy Andrew-Hugill⁷

Graingers experimented with Thermins and changed the speed of recorded sounds on phonograph disks to make Free Music Machine in 1948. Grainers experiments with random music composition predated those of John Cage by 30 years.

He used a Pianola “player piano” controlling three Solovoxes by means of strings attached to Pianola’s.

Free Music machine controlled pitch volume and timbre of 8 oscillators. Two large rollers fed four sets of paper rolls over a set of mechanical arms that rolled over cut contour arms of the papers.

Grainger specified the requirements of his Free Music Machine :

To play any pitch of any size, half, quarter or eighth tones, within the range of 7 voices.
To be able to pass from pitch to pitch by way of a controlled guide as well as by lea.
Complex irregular rhythms must be able to be performed past the scope of human execution.

Conclusion

It was truly an exciting time for electronic music interfaces where there was so much room for experimentation whether it be using light based audio engines, tone wheels, programmable interfaces. There was innovative sound design that was never heard. There were new tuning systems being introduced. The interaction with an instrument was changing as the musician did not have to necessarily play the instrument physically in real time. The Second World war had ended in 1945 and the technological advances made during the war, especially in electronics and radio technology, were redirected toward music instrument design in the late 1940s and 1950s. It got all the more interesting when computers came into being in the 1950s like the ones by IBM.

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Efemello. (2013). Untitled historical photograph [Image]. Retrieved from https://efemeridesdoefemello.files.wordpress.com/2013/11/3nov13.jpg
120 Years of Electronic Music. (n.d.). Mager electric instrument photograph. Retrieved from https://120years-net.stackstaging.com/wp-content/uploads/mager_02.jpg
120 Years of Electronic Music. (n.d.). Cellulophone (Tom Rhea) [Image]. Retrieved from https://120years.net/wp-content/uploads/2023/11/cellulophone_tom_rhea.png
120 Years of Electronic Music. (2024). Electronic instrument archive screenshot. Retrieved from https://120years.net/wp-content/uploads/2024/01/Screenshot-2024-01-19-103505.png
120 Years of Electronic Music. (n.d.). The Voder (Bell Labs) photograph. Retrieved from https://120years-net.stackstaging.com/wp-content/uploads/voder03.jpg
Grainger Society Estate. (n.d.). Percy Grainger’s Kangaroo Pouch Machine [Image]. Retrieved from https://www.researchgate.net/publication/297176138/figure/fig2/AS:922913272250369@1597051079847/Percy-Graingers-Kangaroo-Pouch-Machine-courtesy-The-Percy-Grainger-Society-Estate.ppm