The ‘Audion Piano’ and Audio Oscillator. Lee de Forest. USA, 1915

"The Audion Piano May Entertain Us in the Near Future With Music Purer Than That Obtainable With Any Instrument Now Available. Also it will Imitate Faithfully Any Orchestral Piece." from "Audion Bulbs as Producers of Pure Musical Tones" by Lee De Forest, Electrical Experimenter, December 1915.
“The Audion Piano May Entertain Us in the Near Future With Music Purer Than That Obtainable With Any Instrument Now Available. Also it will Imitate Faithfully Any Orchestral Piece.” from “Audion Bulbs as Producers of Pure Musical Tones” by Lee de Forest, Electrical Experimenter, December 1915.

Lee de Forest , The self styled “Father Of Radio” inventor and holder of over 300 patents, invented the triode electronic valve or ‘Audion valve’  (a portmanteau of ‘Audio’ and ‘Ionise’) in 1906 – a much more sensitive development of John A. Fleming’s diode valve. The immediate application of de Forest’s triode valve was as a more efficient signal detector and amplifier in the emerging radio technology of which de Forest was a tenacious promoter. In 1915 de Forest discovered that the Audion could be used to generate simple audio tones and constructed a rudimentary  electronic instrument – The ‘Audion Piano’. de Forest’s instrument was  the the first true electronic musical instrument in that it generated sound from electrical oscillations (rather than, say, the electro-mechanical generation of sound by the Telharmonium)  – and as such it was the precursor for all the future developments in electronic musical instruments design. The Audion Piano is described in de Forest’s patent of April 24th 1915 ‘Electrical Means for the Production of Musical Notes’:

de Forest’s 1915 patent ‘Electrical Means for Producing Musical Notes.’

The innovations of the Audion Piano were that, as described above, it created sounds through electronic means using a beat frequency or heterodyning effect (a way of creating audible sounds by combining two high frequency signals to create a composite lower frequency within audible range – a technique that was used by Leon Termen in his Theremin and Maurice Martenot in the Ondes Martenot some years later) and that it used electrical capacitance to control the pitch of these tones – techniques used in all electronic instrument designs until vacuum tubes began to be replaced by transistors in the 1960s. The instrument was able to produce eight separate pitches from each bulb and allowed the player to feed variable amounts of the output back into the circuit creating harmonic distortion and timbral effects. The output of the instrument were audible, in this pre-amplifier age, through the sound produced by the bulbs themselves – for public performance the tones were ‘amplified’ using acoustic horns or, like the Telharmonium, distributed over the telephone network.  The pitch and relative tuning of the Audio Piano’s bulbs could be adjusted using simple condensers which could also be manipulated to produce constant glissandi or “siren notes” 1 de Forest, Lee (1915), Electrical Means of Producing Musical Notes, United States Patent Office, June 30th 1925 (Filed April  24th 1915) Pat# 1,543,990.. de Forest, realising that he was able to vary the pitch of the Audion bulbs by touching the circuitry also experimented with body capacitance and claimed that his instrument was the precursor to the Theremin (1922)  and the Hammond Novachord (1939). de Forest later in 1931 sued the RCA corporation – manufacturer of the Victor Theremin – and “all other instruments employing vacuum tubes in the synthetic reproduction of music”  for transgression of the Audion patent. de Forest’s successful petition resulted in a $6,000 award for damages from RCA to the de Forest Co. Although this was not a damaging award, it brought RCA’s production of the Theremin to a halt and had the a long term effect of supressing the commercial development of vacuum tube instruments in the USA.   2 de Forest, Lee,(1950) Father of Radio – THE autobiography OF Lee de Forest, Wilcox & Follet Co, Chicago ILL, 331-2 and 386..

Lee De Forest's Triode Valve of 1906
Lee de Forest’s Triode Valve of 1906

The Audion Piano, controlled by a single keyboard manual, used a single triode valve per octave, controlled by a set of keys allowing one monophonic note to be played per octave. This audio signal could be processed by a series of capacitors and resistors to produce variable and complex timbres and the output of the instrument could be sent to a set of speakers placed around a room giving the sound a novel spatial effect. de Forest planned a later version of the instrument that would have separate valves per key allowing full polyphony- it is not known if this instrument was ever constructed. de Forest described the Audio Piano as capable of producing:

“Sounds resembling a violin, Cello, Woodwind, muted brass and other sounds resembling nothing ever heard from an orchestra or by the human ear up to that time – of the sort now often heard in nerve racking maniacal cacophonies of a lunatic swing band. Such tones led me to dub my new instrument the ‘Squawk-a-phone’….The Pitch of the notes is very easily regulated by changing the capacity or 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 circuit. In this way very weird and beautiful effects can easily be obtained.” 3de Forest, Lee (1950) Father Of Radio – THE autobiography OF Lee de Forest , Wilcox & Follett Co., Chicago, 331-2

And From a 1915 news story on a concert held for the National Electric Light Association

“Not only does de Forest detect with the Audion musical sounds silently sent by wireless from great distances, but he creates the music of a flute, a violin or the singing of a bird by pressing button. The tune quality and the intensity are regulated by the resistors and by induction coils…You have doubtless heard the peculiar, plaintive notes of the Hawaiian ukulele, produced by the players sliding their fingers along the strings after they have been put in vibration. Now, this same effect, which can be weirdly pleasing when skilfully made, can he obtained with the musical Audion.”4de Forest, lee (1915), Audion Bulbs as Producers of Pure Musical Tones, The Electrical Experimenter, Experimenter Publishing Company, Inc. New York, December 1915, 394.

“Diagram of Connections for Creating Pure Musical Tones with Any Audion Bulb.” Electrical Experimenter 1915, New York.

de Forest argued that the Audion Piano was the natural successor to Thaddeus Cahill’s huge Telharmonium  instrument that had  for the previous ten years transmitted electronically generated music to subscribers across the country:

“Several years ago, as the public of New York remembers, a very elaborate undertaking was started for producing music by gigantic electric dynamos mixing the tones from WC or more machines in accordance with the wishes of the skilled performer who in that way produced musical tones of large volume, and which simulated almost those of every instrument in an orchestra. This instrument was termed the telharmonium. The idea was to generate this music at a central station, where highly trained organists were constantly at the keyboard, and distribute it through telephone wires throughout the city to hotels, restaurants, lobbies, concert halls and private residences. This was a most meritorious idea and deserved great success. However, the extraordinary heavy cost of the original plant, the maintenance of the wire cables, etc., rendered it commercially a failure.

Now, with the audion or incandescent lamp as a generator of musical tones, we have on a small scale all of the possibilities of the large telharmonium. Now, this same little bulb which I have just described, in addition to being a receiver of wireless messages and an amplifier for long distance wire telephones (in which use it is now employed on the transcontinental lines of the American Telephone & Telegraph Company), can be made to actually generate alternating current. It receives the energy which is expended in these currents from the dry battery or dynamo. The audion is, in other words, a transformer of energy. The alternating current, if of low frequency, can actuate the telephone diaphragm and make musical notes which the ear can hear, and this is the germ idea involved in the musical instrument which I have just described. The bulbs for musical purposes which I have thus far used are not larger than three inches in diameter.”5de Forest, lee (1915), Audion Bulbs as Producers of Pure Musical Tones, The Electrical Experimenter, Experimenter Publishing Company, Inc. New York, December 1915, 395.

Advert for De Forest wireless equipment - New York, 1916
Advert for de Forest radio telephone & telegraph Co. wireless equipment – New York, 1916

de Forest, the tireless promoter, demonstrated his electronic instrument around the New York area at public events alongside fund raising spectacles of his radio technology. These events were often criticised and ridiculed by his peers and led to a famous trial wherede Forest was accused of misleading the public for his own ends:

“de Forest has said in many newspapers and over his signature that it would be possible to transmit human voice across the Atlantic before many years. Based on these absurd and deliberately misleading statements, the misguided public… has been persuaded to purchase stock in his company. “6(Not Credited), 2001, I Wish I’d Never Said That. Everlasting Gaffes of the Famous, Past Times, Oxford, 2001, 61..
Lee De Forest, August 26, 1873, Council Bluffs, Iowa. Died June 30, 1961
Lee de Forest – Born August 26, 1873, Council Bluffs, Iowa. Died June 30, 1961

de Forest collaborated with a sceptical Thaddeus Cahill in broadcasting early concerts of the Telharmonium using his radio transmitters (1907) – these transmissions were the first broadcast of music using radio and therefore the first musical radio broadcasts were not of live or recorded music but electronic music:7Adams, Mike, (2012) Lee de Forest: King of Radio, Television, and Film, Copernicus, 111.

“Also I had carried a little arc transmitter to the office of the Cahill Telharmonium Company, Broadway and 45th Street, and there energized it from the powerful music currents which they were generating for exhibition and distribution by wire to various halls and restaurants around the city. From my transmitter circuit in their offices a single antenna wire ran up to a flagpole on the roof. By these means I was hoping to show the Cahill brothers that their fine, synthetic, electric music could be widely distributed without wires.”8de Forest, Lee,(1950) Father of Radio – THE autobiography OF Lee de Forest, Wilcox & Follet Co, Chicago ILL, 225.

The New York Tribune reported on the unexpected range of de Forest’s early Telharmonic broadcasts:

“There is music in the air about the roof of the Hotel Normandy these days. A good deal of it is being collected by Lee de Forest’s wireless telephone, ready for distribution to possible purchasers. The power used to transmit the music from the sending apparatus on Telharmonic Hall to the Hotel Normandy was the same used to light an incandescent lamp. Dr. de Forest thought that this would not transmit the music more than a mile at most, but was astonished on Tuesday night when George Davis, chief of the United States Wireless Staff at the Navy Yard, telephoned Telharmonic Hall that the strains of “William Tell” were being mixed up with Naval orders at the Navy Yard five miles away. Yesterday when Dr. de Forest was demonstrating the telephone apparatus, messages from an incoming steamer were intercepted and heard distinctly.”9 New York Tribune, May 15, 1907

Despite this successful proof of concept, Cahill rejected wireless transmission of his instrument – Cahill’s insistence on using the telephone wire network to broadcast his electronic music was a major factor in the demise of the Telharmonium.  Vacuum tube technology was to dominate electronic instrument design until the invention of transistors in the 1960’s. The Triode amplifier also freed electronic instruments from having to use the telephone system as a means of amplifying the signal.


References:

  • 1
    de Forest, Lee (1915), Electrical Means of Producing Musical Notes, United States Patent Office, June 30th 1925 (Filed April  24th 1915) Pat# 1,543,990.
  • 2
    de Forest, Lee,(1950) Father of Radio – THE autobiography OF Lee de Forest, Wilcox & Follet Co, Chicago ILL, 331-2 and 386.
  • 3
    de Forest, Lee (1950) Father Of Radio – THE autobiography OF Lee de Forest , Wilcox & Follett Co., Chicago, 331-2
  • 4
    de Forest, lee (1915), Audion Bulbs as Producers of Pure Musical Tones, The Electrical Experimenter, Experimenter Publishing Company, Inc. New York, December 1915, 394.
  • 5
    de Forest, lee (1915), Audion Bulbs as Producers of Pure Musical Tones, The Electrical Experimenter, Experimenter Publishing Company, Inc. New York, December 1915, 395.
  • 6
    (Not Credited), 2001, I Wish I’d Never Said That. Everlasting Gaffes of the Famous, Past Times, Oxford, 2001, 61..
  • 7
    Adams, Mike, (2012) Lee de Forest: King of Radio, Television, and Film, Copernicus, 111.
  • 8
    de Forest, Lee,(1950) Father of Radio – THE autobiography OF Lee de Forest, Wilcox & Follet Co, Chicago ILL, 225.
  • 9
    New York Tribune, May 15, 1907

Bibliography:

Adams, Mike, (2012) Lee de Forest: King of Radio, Television, and Film, Copernicus.

Collins, N., Schedel, M., & Wilson, S. (2013). Electronic Music (Cambridge Introductions to Music). Cambridge: Cambridge University Press.

de Forest, Lee,(1950) Father of Radio – THE autobiography OF Lee de Forest, Wilcox & Follet Co, Chicago ILL. ( free pdf version here.)

Glinsky, Albert, (2005) Theremin: Ether Music and Espionage, University of Illinois press.

Gurevich, Vladimir, (2005) Electric Relays: Principles and Applications,  CRC Press.

Hong, Sungook, (2001) Wireless: From Marconi’s Black-Box to the Audion, Transformations: Studies in the History of Science and Technology, Cambridge, MA: MIT Press.

Niebisch, Arndt, (2012) Media Parasites in the Early Avant-Garde: On the Abuse of Technology and Communication, Palgrave Macmillan New York.

 

5 thoughts on “The ‘Audion Piano’ and Audio Oscillator. Lee de Forest. USA, 1915”

  1. FYI: The transistor was invented in 1947. Transistor equipment gained in practicality and commercial potential through the ’50’s (for example an all-transistor car radio was introduced in 1955) and by the 60’s it was much more commercially viable (as compared to vacuum tube equipment) than before.

    Your statement “Vacuum tube technology was to dominate electronic instrument design until the invention of transistors in the 1960′s” is substantially true except I’d suggest “widespread commercial viability” instead of “invention.”

    Love your site! Thanks for the cool retro gizmos!

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