The ‘RCA Synthesiser I & II’ Harry Olson & Herbert Belar, USA, 1951

The RCA Mark II Synthesizer at the Columbia-Princeton Electronic Music Center at Columbia's Prentis Hall on West 125th Street in 1958. Pictured: Milton Babbitt, Peter Mauzey, Vladimir Ussachevsky.
The RCA Mark II Synthesizer at the Columbia-Princeton Electronic Music Center at Columbia’s Prentis Hall on West 125th Street in 1958. Pictured: Milton Babbitt, Peter Mauzey, Vladimir Ussachevsky.

In the 1950’s RCA was one of the largest entertainment conglomerates in the United States; business interests included manufacturing record players, radio and electronic equipment (military and domestic – including the US version of the Theremin) as well as recording music and manufacturing records. In the early 50’s RCA initiated a unusual research project whose aim was to auto-generate pop ‘hits’ by analysing thousands of  music recordings; the plan being that if they could work out what made a hit a hit, they could re-use the formula and generate their own hit pop music. The project’s side benefit also explored the possibility of cutting the costs of recording sessions by automating arrangements and using electronically generated sounds rather than  expensive (and unionised) orchestras; basically, creating music straight from score to disc without error or re-takes.


The RCA electrical engineers Harry Olson and Hebart Belar were appointed to develop an instrument capable of delivering this complex task, and in doing so inadvertently (as is so often the case in the history of electronic music) created one of the first programmable synthesisers – the precursors being the Givelet Coupleux Organ of 1930 and the Hanert Electric Orchestra in 1945.

Paper punch roll showing parameter allocation
Paper punch roll showing parameter allocation

The resulting RCA Mark I machine was a monstrous collection of modular components that took up a whole room at  Columbia University’s Computer Music Center  (then known as the Columbia-Princeton Electronic Music Center). The ‘instrument’ was basically an analogue computer; the only input to the machine was a typewriter-style keyboard where the musician wrote a score in a type of binary code.


Paper-punch input of the RCA Synthesisir
Paper-punch input of the RCA Synthesisir
Punch paper terminals of the RCA MkII
Punch paper terminals of the RCA MkII

The keyboard punched holes in a pianola type paper role to determine pitch, timbre, volume and envelope – for each note. Despite the apparent crudeness of this input device, the paper roll technique allowed for complex compositions; The paper role had four columns of holes for each parameter – giving a parameter range of sixteen for each aspect of the sound. The paper roll moved at 10cm/sec – making a maximum bpm of 240. Longer notes were composed of individual holes, but with a mechanism which made the note sustain through till the last hole. Attack times were variable from 1 ms to 2 sec, and decay times from 4 ms to 19 sec. On the Mark II, High and low pass filtering was added, along with noise, glissando, vibrato and resonance,  giving a cumulative total of millions of possible settings.

Structure of the RCA MkII
Structure of the RCA MkII
RCA Synthesiser structure
RCA Synthesiser structure

The sound itself was generated by a series of vacuum tube oscillators (12 in the MkI and 24 in the MkII) giving four voice polyphony which could be divided down into different octaves . The the sound was manually routed to the various components – a technique that was adopted in the modular synthesisers of the 1960’s and 70’s. The eventual output of the machine was  was monitored on speakers and recorded to a lacquer disc, where, by re-using and bouncing the disc recordings, a total of 216 sound tracks could be obtained. In 1959 a more practical tape recorder was substituted.

Babbit, Luening, Ussachevsky and others at the RCA MkII
Babbit, Luening, Ussachevsky and others at the RCA MkII

It seems that by the time the MkII Synthesiser was built RCA had given up on their initial analysis project. Mainstream musicians had baulked at un-musical interface and complexity of the machine; but these very same qualities that appealed to the new breed of serialist composers who took the RCA Synthesiser to their heart;

The number of functions associated with each component of the musical event…has been multiplied. In the simplest possible terms, each such ‘atomic’ event is located in a five-dimensional musical space determined by pitch-class, register, dynamic, duration, and timbre. These five components not only together define the single event, but, in the course of a work, the successive values of each component create an individually coherent structure, frequently in parallel with the corresponding structures created by each of the other components. Inability to perceive and remember precisely the values of any of these components results in a dislocation of the event in the work’s musical space, an alteration of its relation to all other events in the work, and–thus–a falsification of the composition’s total structure…

Why should the layman be other than bored and puzzled by what he is unable to understand, music or anything else?…Why refuse to recognize the possibility that contemporary music has reached a stage long since attained by other forms of activity? The time has passed when the normally well-educated [person] without special preparation could understand the most advanced work in, for example, mathematics, philosophy, and physics. Advanced music, to the extent that it reflects the knowledge and originality of the informed composer, scarcely can be expected to appear more intelligible than these arts and sciences to the person whose musical education usually has been even less extensive than his background in other fields.

I dare suggest that the composer would do himself and his music an immediate and eventual service by total, resolute, and voluntary withdrawal from this public world to one of private performance and electronic media, with its very real possibility of complete elimination of the public and social aspects of musical composition. By so doing, the separation between the domains would be defined beyond any possibility of confusion of categories, and the composer would be free to pursue a private life of professional achievement, as opposed to a public life of unprofessional compromise and exhibitionism.

But how, it may be asked, will this serve to secure the means of survival for the composer and his music? One answer is that, after all, such a private life is what the university provides the scholar and the scientist. It is only proper that the university which–significantly–has provided so many contemporary composers with their professional training and general education, should provide a home for the ‘complex,’ ‘difficult,’ and ‘problematical’ in music.

Milton Babbitt

Among the composers who used the machine frequently were the Princeton composer Milton Babbitt and Charles Wuorinen, the latter of whom composed the Pulitzer Prize-winning “Time Econium” on it in 1968.

RCA Synthesiser
RCA Synthesiser

The pioneering RCA Synthesiser became obsolete and fell out of use in the early 1960s with the arrival of cheaper and reliable solid state transistor technology and the less complex programming interfaces of instruments such as the Buchla and Moog range of synthesisers. Neither machine survives in working condition today. The MkI  was dismantled during the 1960s (parts from it cannibalised to repair the MkII). The MkII is still at Columbia University’s Computer Music Center, but has not been maintained and reportedly is in poor condition, it was vandalised sometime in the early 1970’s and little used after that.

Images of the RCAI& II



RCA issued a box set of four 45 RPM extended-play disks with a descriptive brochure.  This set featured a narration and demonstration of the basic features of the synthesizer, and concluded with renditions of several well known popular and classical pieces “played” on the synthesizer:

Side 1: The Synthesis of Music-The Physical Characteristics of Musical Sounds (7:13, 3.3 mb)
Side 2: The Synthesis of Music-Synthesis by Parts (Part 1) (5:55, 2.7 mb)
Side 3: The Synthesis of Music-Synthesis by Parts (Part 2) (4:37, 2.1 mb)
Side 4: Excerpts from Musical Selections (Part 1) (6:05, 2.8 mb)
Side 5: Excerpts from Musical Selections (Part 2) (3:28, 1.6 mb)
Side 6: Complete Selections-Bach Fugue No. 2, Brahms Hungarian Dance No. 1 (4:47, 2.2 mb)
Side 7: Complete Selections-Oh Holy Night (Adam), Home Sweet Home (Bishop) (6:42, 3.1 mb)
Side 8: Complete Selections-Stephen Foster Medley, Nola (Arndt), Blue Skies (Berlin) (7:49, 3.6 mb)



The Wurlitzer ‘Side Man’ Rudolph Wurlitzer Company, USA, 1959

Sideman advertisement. Popular Mechanics, November 1960

The Rudolph Wurlitzer Company released an early commercially produced drum machine called the Sideman in 1959. It was an “electro-mechanical” drum machine that offered a choice of 12 electronically generated predefined rhythm patterns with variable tempos. The sound source was a series of vacuum tubes which created 10 preset electronic drum sounds. The drum sounds were ‘sequenced’ by a rotating disc with metal contacts across its face, spaced in a certain pattern to generate parts of a particular rhythm. Combinations of these different sets of rhythms and drum sounds created popular rhythmic patterns of the day, e.g. waltzes, fox trots etc.

Sideman control panel
Sideman control panel

These combinations were selected by a rotary knob on the top of the Sideman box. The tempo of the patterns was controlled by a slider that increased the speed of rotation of the disc. The Sideman had a panel of 10 buttons for manually triggering drum sounds, and a remote player to control the machine while playing from an organ keyboard. The Sideman was housed in a portable wooden cabinet that contained the sound generating circuitry, amplifier and speaker.




‘Buchla Synthesisers’, Donald Buchla. USA, 1966.

Buchla Series 100
Buchla Series 100 ‘Buchla Box’

Donald Buchla created his first electronic instruments in 1960 in response to a commission from the avant-garde composer Morton Subotnik. Subotnik was searching for a replacement for the large complex electronic music studios of the day where most ‘serious’ avant-garde music was composed and recorded: for example RAI studio Milan and WDR Studio Köln, Germany and GRM Paris, France . These studios consisted of multiple individual oscillators, processor units, filters and mixers that, with the help of trained technicians (each of the studios had its own unique system), could be manually patched together. The advent of transistor technology allowed much of this process to be miniaturised into a single portable, standardised version of the electronic music studio but restaining the modular, patchable approach:1Trevor Pinch, Frank Trocco (2004), Analog Days, Harvard University Press.

Series 100 from the original brochure of the San Francisco Tape studio.

The offspring of a technology which is itself but half a century old, electronic music is in its infancy. Instruments specifically designed for its production have been crude and generally unavailable. Therefore, the basic objectives for development of the Modular Electronic Music System were:

1. The achievement of direct, immediate control of musical parameters. Instruments should be played in real time, eliminating such note-forming routines as: set frequency – start recorder – stop recorder – measure – cut – splice – repeat, etc.

2. Compatibility of all equipment, Rules for interconnecting equipment to be straight-forward and consistent. Interfacing with external equipment (recorders, tuners, microphones, etc.) should be readily accomplished.

3. Fully transistorized circuitry, employing conservative design and high quality components. Reliable operation with minimal maintenance must be realized.

4. A special requirement for the system was that the equipment be lightweight and portable, thus making feasible its use in the composer’s home, the concert hall, and on tour.

5. Without compromising other design objectives, cost should be low. Power supplies and cabinetry should be common to several unity, and modular construction should be employed to permit economical system expansion.

2The Modular Electronic Music System, (1960), San Francisco Tape Music Center, 2.
Donald Buchla
Donald Buchla

With a $500 grant from the Rockefeller Foundation Buchla started building his first modular synthesisers in 1963 at the  San Francisco Tape Music Center, the hub of experimental and electronic music at the time, founded by  composers Morton Subotnick and Ramon Sender and used by artists such as  Terry Riley, Pauline Oliveros, Steve Reich, William Maginnis and Tony Martin. Buchla’s early synthesisers were experimental in design reflecting the experimental music they were intended to produce. Buchla’s designs utilised many unique and unusual features such touch sensitive and resistance sensitive plates. One of Buchla’s innovative inventions from this period was the first analogue sequencer.

Buchla Associate’s  first production model synthesiser was the Buchla Series 100 or ‘Buchla Box’ (or ‘Electronic Music Box’ as Buchla preferred ): a keyboardless modular synthesiser.  The Buchla Box was manufactured in 1966 through a licensing deal with CBS/Fender – a deal that quickly stalled as CBS/Fender pulled out citing a lack of   but  (who soon closed the deal, seeing no future in electronic instruments).

The Series 100 was an innovative electronic instrument with a logically laid out, intuitive front panel allowing the user to patch and route modules with patch cords (To avoid confusion, the Series 100 uniquely, and unlike the Moog Modular, used separate patch cords for output and control voltages allowing the patching of multiple control voltages with stack-able ‘Banana’ patch cords) designed primarily with the electronic music composer in mind . The manual control of the instrument reflected the concerns of the time around microtonality and the limitations of the tempered scale keyboard; Buchla, very much in the ‘serious’ experimental music camp designed the instrument to be set up and run to produce a continuous piece; more of an electronic music studio than an instrument per-se. The composer could trigger and manipulate multiple parameters using an array of pressure sensitive touch pads or ‘Kinaesthetic input ports’ to free themselves from the constraints of a standard keyboard:

“They [the ports] were all capacitance-sensitive touch-plates, or resistance-sensitive in some cases, organized in various sorts of arrays…I saw no reason to borrow from a keyboard, which is a device invented to throw hammers at strings, later on, for operating switches for electronic organs and so-on. A keyboard is dictatorial. When you’ve got a black and white keyboard there it’s hard to play anything but keyboard music – And when there’s not a black and white keyboard you get into the knobs and the wires and the interconnections and timbres, and you get involved in many other aspects of the music, and it’s a far more experimental way. It’s appealing to fewer people but it’s more exciting”
Donald Buchla

3Don Buchla retrieved 06-08-2021
The original Buchla Box - signed by Ken Kessey
The original Buchla Box – signed by Ken Kesey

One of the main innovations of the series 100 was the inclusion of one of the first analogue sequencer modules ; Three sequencers were fit into the first Buchla synth, two with eight stages, the third with 16

” There were three voltage-controlled outputs for each stage. I used to cascade two sequencers so that they would run simultaneously, giving you six voltages per stage. One voltage would control pitch, another spatial location, the third amplitude. Then one, which was really clever, would control the pulse generator that was controlling the sequencer, so that you could determine the absolute rhythm. You could literally program a very complex rhythm over a long period of time, for example, by running five stages against 13.'”
Morton Subotnick

Modules of the ‘Buchla Box’ :

Module Number Description
M.101 wooden case for 25 modules
M.106 six channel mixer
M.107 voltage-controlled mixer
M.110 Dual Voltage-controlled Gates
M.111 Dual Ring Modulator
M.112 12 touch-controlled voltage sources (capacitive keyboard)
M.114 10 touch-controlled voltage sources (capacitive keyboard)
M.115 power supply
M.123 Sequential Voltage Source (8-step sequencer)
M.124 patchboard
M.130 Dual Envelop Generator
M.132 wave-form synthesizer
M.140 timing pulse generators
M.144 Dual Square-wave Generator
M.146 Sequential Voltage Source (sequencer, 16 step X 3 layer)
M.148 Harmonic Generator
M.150 Frequency Counter
M.156 Dual Control Voltage Counter
M.158 Dual Sine / Sawtooth Oscillators (VCOs)
M.160 White Noise Generator
M.165 Dual Random Voltage Source or ‘Source Of Uncertainty’
M.170 Dual Microphone Amplifier
M.171 Dual Instrument Pre-amplifier
M.175 Dual Equalizer / Line Driver
M.180 Dual Attack Generator
M.185 Frequency Shifter
M.190 Dual Reverberator
M.191 sharp cut-off filter
M.192 dual low pass filter
M.194 bandpass filter
M.195 octave formant filter
M.196 phase shifter

The Series 100 was followed by the Buchla Series 200 Electronic Music Box in 1970. The ‘Buchla Box’ was much used during the Acid Test psychedelic happenings of the Haight-Ashbury era by rock groups such as the Grateful Dead (“and later, provided the sounds for R2D2 in the film series Star Wars” – corrected – see comments section).

Buchla Series 200e of 1970. image: Sound on Soun 2005

Around this time affordable mini-computers became available and Buchla created the first digitally controlled analogue synthesiser, the Buchla 500 series in 1971. This was followed by the ‘Buchla Music Easel’ in 1972  Touché (1978), the Buchla 400 (1982), the Buchla 700 (1987). More recent products have included MIDI controllers and re-vamped versions of the Series 200.

Buchla Music Easel 1972
Buchla Music Easel 1972
Buchla Series 700
Buchla Series 700


  • 1
    Trevor Pinch, Frank Trocco (2004), Analog Days, Harvard University Press.
  • 2
    The Modular Electronic Music System, (1960), San Francisco Tape Music Center, 2.
  • 3
    Don Buchla retrieved 06-08-2021

The ‘Telharmonium’ or ‘Dynamophone’ Thaddeus Cahill, USA 1897

The dual manual of the MkII Telharmonium. Gunter's Magazine June 1907
The dual manual of the MkII Telharmonium. Gunter’s Magazine June 1907

In 1895 Thaddeus Cahill submitted his first patent for the Telharmonium “The Art of and Apparatus for Generating and Distributing Music Electrically”. The Telharmonium can be considered the first significant electronic musical instrument and was a method of electro-magnetically synthesising and distributing music over the new telephone networks of victorian America.

Thaddeus Cahill's patent documents for the first Telharmonium 1896
Thaddeus Cahill’s patent documents for the first Telharmonium of 1897 showing the arrangement of rotor alternators and rheostat brushes.

This first patent was initially rejected by the patent office because the “plan contained principles and practices found in other patented devices”. Cahill, a trained lawyer, eventually succeeded in having his patent accepted in 1897.

The first design of the instrument set out the principles of the ‘Telharmonium’ or ‘Dynamophone’ that would be developed by Cahill over the next twenty years. Cahill’s vision was to create a universal ’perfect instrument’; an instrument that could produce absolutely perfect tones, mechanically controlled with scientific certainty. The Telharmonium would allow the player to combine the sustain of a pipe organ with the expression of a piano, the musical intensity of a violin with polyphony of a string section and the timbre and power of wind instruments with the chord ability of an organ. Having corrected the ‘defects’ of these traditional instruments the superior Telharmonium would render them obsolete.

Thaddeus Cahill's patent documents for the first Telharmonium of 1897
Thaddeus Cahill’s patent documents for the first Telharmonium of 1897 showing tone rotor shafts

The other innovative aspect of Cahill’s design was that he proposed to distribute the electronic musical output of the instrument over the newly established telephone network to subscribers at home or in hotels and public spaces; hence the name ‘Telharmonium’ – ‘Telegraphic Harmony’. This was partly due to the fact that the only way of hearing the instrument in the pre-amplifier and loudspeaker era was via an acoustically amplified telephone receiver.


In 1885 Hermann Helmholtz’s ‘On the Sensations of Tone’ (1862) appeared in English translation and had an immediate and profound impact on scientific and musical thinking. Helmholtz defined the concept that a tone was composed of a single fundamental sound which, combined with a set of higher sounds, gave each musical tone a unique quality or timbre – and that these tones were a collection of ‘pure’ sine tone. Cahill’s reasoning was that the ‘perfect instrument’ could be built to created sine tones that could be combined to recreate the qualities of existing instruments without their ‘defects’.

The German edition of Helmholtz's ‘On the Sensations of Tone’ (1862)
The German edition of Helmholtz’s ‘On the Sensations of Tone’ (1862)

The idea of transmitting music over he telegraphic or Telephone network was not new. Cahill was well aware of previous inventions and experiments with Telegraphic music.

Soemmerring's musical telegraph
Soemmerring’s musical telegraph of 1809

As far back as 1809,the Prussian anthropologist, paleontologist and inventor Samuel Thomas Soemmerring created an electrical telegraph that triggered an array of tuned bells from a distance of several kilometres. This experiment was originally as an intended as an investigation into human consciousness and perception but led to speculation about the possibilities of transmitting music electronically over great distances.

Poster for the Budapest Telefonhírmondó
Poster for the Budapest Telefonhirmondo

In 1893 the Hungarian engineer and inventor Tivadar Puskás established the ‘Telefonhírmondó’ or ‘Telephone Herald’ a type of telephone based newspaper that broadcast music and news over the telephone network in Budapest to as many as 91,000 subscribers which continued (in tandem with a radio service) until World War II when the wire network was destroyed.


In Paris, Clément Ader created the ‘Théâtrophone’ a type of early binaural or stereo audio transmission of music and theatre in 1881 which ran until it was superseded by radio in 1931 and similarly, in London in 1895, the ‘Electrophone’ service distributed music hall and light music to an audience of subscribers.

But probably the biggest technical influence on Cahill was Elisha Gray’s ‘Musical Telegraph’ of 1874. Gray, one of the inventors of the telephone, had developed a way of  transmitting pitched tones over a long distance telegraph network using electromagnetically controlled vibrating metal reeds. Gray had originally intended to use this as a way of sending multiple messages over a network ( a predecessor of multiplex signals)  and had created a musical keyboard instrument to promote his ideas. It was the similarity of Gray’s work to Cahill’s initial concept that led to the rejection of Cahill’s first patent and in response Cahill was scathing about Gray’s instrument declaring that the Musical Telegraph was:

“practically useless. No person of taste or culture could be supposed to derive any enjoyment from music rendered in poor, harsh tones, with uneven power, and absolutely without expression or variation.”

…and that Gray’s patented machine was unable to produce sine waves or complex harmonics of the Telharmonium;

“…do not produce undulations of current; they produce sharp, violent (tones). (The device) unavoidably adds to the partials desired many which are injurious — so many, that his patent . . . seems … to wholly break down.”

Cahill restructured his patent to accentuate the differences between his invention and that of Elisha Gray – nevertheless, Gray’s ‘Musical Telegraph’ clearly had a major influence on Cahill’s new instrument.

Scientific American vol 96 no10 9th March 1907
The Telharmonium in the ‘Scientific American’ vol 96 #10 9th March 1907

The ‘Telharmonium’ or ‘Dynamaphone’

Cahill’s major criticisms of Gray’s ‘Musical Telegraph’ was that by using electromagnetically oscillating metal reeds, Gray’s instrument only had enough power to be heard at close range to a telephone receiver and, the Musical Telegraph’s oscillators could only create harsh, simple tones that lacked character and expression. Cahill’s proposal was to generate complex mixtures of sine tones using multiple electrical dynamos that would be powerful enough to be audible to an audience from a distance.

A single tone wheel generator
A single tone wheel generator with eight alternators.

The core of his invention was the tone wheel; essentially a rotor with variably shaped alternators  that spun within a magnetic field (The early versions used rheotomes; a set of brushes that contacted the rotor as it spun.) to generate a tone. Each tone wheel was composed of the fundamental tone and six ascending partials. The first model consisted of a mainframe of twelve identical rotors each of the twelve pitch-rotors carried seven fundamental alternators, six third-partial alternators, and five fifth-partial alternators. These rotors were spun at the relevant speed by a belt driven motor, giving the instrument a six octave range. This arrangement gave the Telharmonium two tuning systems; one being a pure harmonic series used for building the timbre of each note, and the other, an equal tempered scale used for combining notes into a scale.

Diagram showing frequencies of the Telharmonium alternators. image from ‘Magic Music from the Telharmonium’ By Reynold Weidenaar

The output quality of the tone wheels – especially with the rheotome versions – was harsh and unpleasant. The sound quality was softened by passing the signal through a series of secondary induction coils that filtered the harshness from the sound to a tone approximating a sine wave. (These induction could could also be controlled by the velocity of the keyboard, allowing the musicians a complex level of expressive influence over the tone.). Cahill was able to dispense with these purifying circuits in later models after perfecting rotor teeth cutting techniques to provide an almost pure sinusoidal output.

The number of partials for each fundamental could be controlled with familiar organ like stops allowing the instrument to imitate orchestral instruments. In this way, the Telharmonium was the first additive synthesiser; recreating instrumental timbres by adding and mixing harmonics.

The idiosyncratic 3 manual version of the MkI Telharmonium
The idiosyncratic 3 manual version of the MkI Telharmonium
Dual manual of the MkII Telharmonium. Gunters Magazine 1907.

Less familiar was the keyboard arrangement; for the second Telharmonium, Cahill hired the pianist Edwin Hall Pierce to develop a repertoire for the instrument as well as create sounds from the multiple harmonics. Pierce, with Cahill, also defined the unusually complex keyboard arrangement. Because the Telharmonium mechanically created notes using exact divisions that equated to just intonation, Pierce decided to use three sets of keyboards (two or sometimes four in later models) that allowed for thirty six keys per octave (over the three keyboards) – this meant that instead of the usual black and white key layout, the manual consisted of alternate black and white keys and the player had to learn to play over three manuals to achieve an equal tempered scale. Despite this nightmarish keyboard-complexity the Telharmonium had the unique ability – if required – to play over a variety of intonations.

Patent documents of the Telharmoinium
Patent documents of the Telharmoinium

A unique clutch like device allowed the player to control expression using key velocity as well as with a foot pedal. The resulting sound was fed through the wire network and streamed to the audience through large, six-foot acoustic horns of various designs– Cahill experimented with numerous horn designs using different thicknesses of wood, metal carbon and paper to acquire the right range of tones.

Acoustically resonating speaker of the Telharmonium.
Acoustically resonating speaker of the Telharmonium. 1917 patent.

For the Telharmonium to be audible beyond a telephone receiver it needed a much more current than the standard telephone; the output power from the Telharmonium’s alternators was as much as 15,000 watts and around 1 amp at the receiver – compared to a telephone receiver designed for currents as low as six ten-trillionths of an amp. This power did allow the Telharmonium to be audible to an audience but caused interference with the New York telephone network and needed a huge amount of electricity to keep it running.

Tone rotors of the MkII Telharmonium in the basement of Telhamronic Hall c 1907
Two of the tone rotors of the MkII Telharmonium in the basement of Telhamronic Hall circa 1906. Image from McCLure’s Magazine 1906

The sound of the Telharmonium

The first description of the sound of the Telharmonium was from Ray Stannard Baker writing for McClure’s magazine describing a demonstration of the Washington MkI Telharmonium at the Hotel Hamilton;

“The first impression the music makes upon the listener is its singular difference from any music ever heard before : in the fullness, roundness, completeness, of its tones. And truly it is different and more perfect: but strangely enough, while it possesses ranges of tones all its own, it can be made to imitate closely other musical instruments: the flute, oboe, bugle, French horn and ‘cello best of all, the piano and violin not as yet so perfectly. Ask the players for fife music and they play Dixie for you with the squealing of the pipes deceptively perfect. Indeed, the performer upon this marvelous machine, as I shall explain later, can “build up” any sort of tone he wishes : he can produce the perfect note of the flute or the imperfect note of the piano — though the present machine is not adapted to the production of all sorts of music, as future and more extensive machines may be.

After several selections had been given I was conscious of a subtle change in the music. Dr. Cahill said: “Mr. Harris has taken Mr. Pierce’s place.”

It is quite as possible, indeed, to distinguish the individuality of the players upon this instrument as it is upon the piano or violin. The machine responds perfectly to the skill and emotion of the player; he gets out of it what he puts into it: so that the music is as much a human production as though the player performed upon a piano. In an hour’s time we had many selections, varying all the way from Bach and Schubert to the ” Arkansas Traveler ” and a popular Stein song. One duet was played by Mr. Pierce and Mr. Schultz. The present machine is best adapted to the higher class of music. It does not produce with any great success the rattlebang of rag-time which is perhaps an advantage”

Ray Stannard Baker writing in McClure’s Magazine.  1903

And Thomas Commerford Martin writing in the Outlook on the 5 May ;

“A skillful performer upon the telharmonium can make it blare like a trumpet, snarl like a bassoon, warble like a flute, or sing like a violin. Four or five performers, playing in concert, will ultimately be able, it is believed, to produce an effect closely approaching that of a full orchestra ; for each bank of keys is furnished with a set of stops somewhat like those of an organ, by means of which it can be made to produce tones almost if not quite identical with those of any family of instruments. At one keyboard one player can play the part of the strings ; at another a second player can reproduce the tones of the oboe family ; at another a third player can reproduce the tones of the brass ; and so on. And each player is able in an instant to modify or transform the quality of tone which he is producing.

Of course there are limitations in this power to imitate instruments. In the violin tone on the telharmonium there is nothing of resin and catgut ; in the tone of the French horn there is not the occasional break characteristic of that instrument. On the other hand, the quality of tone in the telharmonium is capable of infinite variation.- Instrumental effects are possible on it which have never before been heard.”

The Telharmonic Hall, New York City circa 1906
An audience at Telharmonic hall enjoying a concert of Telharmonic music played through carbon-arc lamps.
An audience at Telharmonic hall enjoying a concert of Telharmonic music played through carbon-arc lamps. Gunter’s Magazine June 1907
A gospel service accompanied by the Telharmonium at Telharmonic Hall. Gunter's Magazine June 1907
A gospel service accompanied by the Telharmonium at Telharmonic Hall. Gunter’s Magazine June 1907
The future of music. A photograph from Gunter's Magazine June 1907 that imagines the future of electronic music played to households through carbon-arc lamps
The future of music. A photograph from Gunter’s Magazine June 1907 that imagines the future of electronic music played to households through carbon-arc lamps

Established at the Telharmonic Hall Cahill’s New York Electric Music Co. put on several seasons of Telharmonic music from 1906 – including guided tours of the basement machinery. The repertoire consisted of popular light classical works that emphasised the instrument’s range and flexibility. The audience listed to the music using a variety of horns and speakers including music fed into a series of carbon arc lamps that oscillated with the electronic signal giving an audio and light show (this phenomena had been explored by the British physicist William Duddell and was used in his ‘Singing Arc’ instrument of 1899)

Programm for Telharmonic Hall concerts
Programm for the Telharmonic Hall concerts

Ray Stannard Baker in McClure’s magazine in 1903 also contemplated the effect the Telharmonium would have on music and the listener arguing that it would ‘democratise’ music:

“As the machine is developed, and as the players become more expert, we may enter upon quite a new era of music, what ma)’ be called, indeed, the democracy of music. We cannot really herald the complete dominance of democracy until we have good music, great pictures, and the best books at the command of every citizen. Museums, galleries, and process printing have gone far towards bringing that equal opportunity of all citizens for the enjoyment of great pictures, which is the dream of the social philosopher. Free libraries have placed the best and rarest books at the command of any man who wishes to use them. But music, by its nature ephemeral and costly of production, has not so easily submitted itself to such democracy of enjoyment. Poor music may be had anywhere: good music is it is hived up in grand opera houses, and supported by playing upon the social vanity of the rich. It is a pastime for society. To this fact, indeed, may be traced the slow development, much deplored by critics, of musical taste in this country.”

The Three Telharmoniums

In all Cahill designed and built three versions of the Telharmonium (with five patents);

The, MkI version, as described in his 1897 patent, Cahill built by hand in his laboratory in Washington and, weighing a mere 14,000lbs was essentially a working prototype designed to raise capital for a planned full version .

The Cabot St Mill, Hollyoke, Mass as it is today.
The Cabot St Mill, Hollyoke, Mass as it is today.

Once enough interest had been generated to finance the development of the Telharmonium Cahill and his associated moved to the Cabot St Mill in Holyoke, Mass. where construction of the much larger MkII commenced in 1902. the MkII was constructed by a workforce of fifty engineers, grinders, reamers, assemblers and other workers under the guidance of Cahill.

Keyboard players of the MkII Telharmonium
Keyboard players of the MkII Telharmonium

The MkII consisted of  eight 11” steel shafts bearing a total of 145 alternators. The 60-foot mainframe was built of 18” steel girders set on brick foundations. Ten switchboard panels contained almost 2,000 switches. The whole apparatus weighed 200 tons and cost $200,000 and assumed the proportions and appearance of a power station generator.

The switchboard and tone circuits of the MkII

It was this version that was disassembled in 1906 and transported to by railroad to be installed at the ‘Telharmonic hall’ on 39th Street and Broadway New York City where it was previewed to an audience of nine hundred people. The MkII Telharmonium remained in NYC for another four years giving regular concerts and ‘broadcasts’ at the Telharmonic Hall and other fashionable venues across the city. Despite it’s initial success the subscriber business foundered after the 1907 financial panic and Telharmonic Hall closed in 1910.

Audience at the Cafe Martin where the Telharmonium was broadcast
Audience at the Cafe Martin, New York City where the Telharmonium was broadcast

After the collapse of the ‘Telharmonic Hall’ business, Cahill regained control of the rights to his invention and stoically rebuilt and refined the design to create the final MkIII version back at the Cabot St mill. The Mk III, again weighing 200 tons but with a number of significant improvements including new alternator designs and a standard keyboard for a tempered scale,  was installed in the basement of a building on west 56th st NYC. It was here that the Telharmonium made it’s final debut in Feb 1912 streaming music to the Chapter room of Carnegie Hall. Despite Cahill’s improvements and tireless promotion of the instrument, ‘Telharmony’ had lost the novelty value that sustained public interest six years previously and subscribers failed to materialise. Cahill finally filed for bankruptcy in 1914. The  MkII and III Telharmoniums were sold for scrap. The remains of the first Telharmonium were kept  by Cahill’s brother Arthur but were also scrapped after his death in 1958.


Dr. Thaddeus Cahill’s system of generating music at a central station in the form of electrical oscillations, and of transmitting these oscillations by means of wires to any desired point, where they are rendered audible by means of an ordinary telephone receiver or a speaking arc, is now embodied in a working plant situated in the heart of New York. Although this apparatus constitutes b.ut a portion of a plant that may ultimately assume very remarkable dimensions, and although it has limitations imposed by its size, the results obtained are so promising, that many applications have been made by prospective subscribers for connection with the central station. When a larger number of · generators and keyboards is installed, as they doubtless will be in due time, there is no reason why the telharmonium, as the invention is called, should not give the subscribers all the pleasures of a full symphony orchestra whenever they wish to enjoy them. At present ‘ very beautiful effects are secured on a . less elaborate scale, but in eveI\ly way comparable with those of a good quintet.. And several additional keyboards now in building at Dr. Cahill’s works at Holyoke, Mass., where the New York plant was built, are nearing completion, and will probably be in service at Broadway and Thirty-ninth Street in the course of another month or two.

Perhaps the feature which most astonishes the technically Uninformed man when Dr. Cahill’s invention is first exhibited to him is the fact that music in the ordinary sense of the word, in other words, rhythmic vibrations of the air, is not produced at the central station. The vibrant notes of the flute, mingled with the clarinet or viol-like tones which are heard at the receiving end of the wire, spring from no musical instrument whatever. Nowhere is anything like a telephone transmitter used, although the electrical oscillations which are sent to the receiver and there translated into audible vibrations are quite like those set up in an ordinary telephone circuit, except that they are enormously more powerful.

Briefly summed up, Dr. Cahill’s wonderful invention consists in generating electrical oscillations corresponding in period with the acoustic vibrations of the various elemental tones desired, in synthesizing from th ese electrical vibrations the different notes and chords required, and in rendering the sYnthesized electrical vibrations audible by a translating device.

In the New York plant the electrical vibrations are produced by 144 alternating dynamos of the inductor type, having frequencies that vary from 40 to 4,000 cycles. These alternators are arranged in eight sections or panels, each inductor being mounted on an ll-inch steel shaft. One inductor dynamo is used for each note of the musical scale, each generator producing as many electrical vibrations per second as there are aerial vibrations in that note of the musical scale for which it stands. The fixed or stator part of each dynamo carries both the field and armature windings ; the rotors are carried on shafts geared together, the number of teeth ( pole pieces) on the gear wheels corresponding with the number of frequencies to be ob-. tained. Because the rotors are geared together, the frequencies are fixed and tuning is unnecessary. The alternators are controlled each by a key in a keyboard upon which the musician plays. Each key serves to make and break the main eircuit from seven alternators, not directly, but through the medium of plunger relay magnets wound with layers of enameled wire. Only feeble and harmless currents are needed to control the relay magnets, by which the task of making and breaking the currents from the main circuits is r’eally performed. No appreciable ‘ time elapses between the depression of a key and the closing of a main alternating circuit, so that the keyboard is as responsive and sensitive as that of a piano. The elemental notes generated by the . 144 dynamos cannot alone be used to produce the most pleasing musical effects.

Why this should be so becomes apparent from a consideration of some Simple principles in acoustics. If a wire be stretched between two points A and B (see the accompanying diagram) and plucked or struck, it will vibrate above and below the line A, B and give what is known as a fundamental tone. This fundamental tone is without distinctive musical character or timbre, and would sound the same in all instruments, so that one could not distinguish whether it came from a violin or a piano. In addition to its fundamental vibration between its pOints of attachment, the string undergoes a series of sub-vibrations above and below its own normal curve, which it will pass at certain points, nodes, dividi????g it into equal parts. Thus in the accompanying sketch, A, 0, B and A, D, B represent the fundamental Vibrations, and A, E, 0, F, B, the first sub-vibration intersecting the fundamental vibration at the node 0. Again, the string may vibrate in three parts, four parts, five parts, etc. The effect of the sub-vibrations is added to the effect of the fundamental vibration, and their total effect is heard in the distinctive quality or “tone Color,” as it is called, of the particular instrument played. The sub-vibrations are known as the upper partials or overtones, and generally speaking, they are harmonious with one another and with the fundamental tone. That very elusive and uncertain quality called timbre is dependent entirely upon these overtones. By properly controlling the blending of the overtones and the elemental tones, it ought to be possible to. imitate the characteristic timbre of any musical instrument. This Dr. Cahill has in a large measure succeeded in accomplishing.

“Tone mixing,” as this building up of harmonious notes and chords is called, is effected in the telharmonium by superposing the simple or sinusoidal waves of the alternators. By means of bus-bars the oscillations of the ground tones are all brought together in one circuit, those of the first partials in another circuit, those of the second partials in a third circuit, etc. The actual blending is done by passing the various oscillations through a series of transformers. In order to understand how a chord is blended, we must begin at the keyboard. As soon as the performer depresses his keys, the bus-bars electrically superpose the ground tone currents , through the primaries of closed-iron magnetic circuit transformers, the secondaries of which are jained in circuit with impedance rheostats governing the strength of the currents, which rheostats are controlled from the keyboard by means of stops. Similarly the bus-bars superpose the first, second, third, and other desired partials in separate circuits. The composite ground-tone a’nd overtone oscillations thus produced in the secondaries of the transformers are next passed through the primaries of an open-iron magnetic circuit transformer, in the secondary circuit of which a current is produced composed of all the ground tone and overtone frequencies of the particular chord under consideration. This secondary current is in turn passed through the primary of an air-core transformer, and the resultant secondary current is converted by telephone receivers or speaking arcs into the musical chord desired.

In order to listen to this musical chord, the telephone receiver is not held to the ear. It would be bad for the ear if it were, when a loud note is sounded. The current of the receiver is literally thousands, and at times millions of times stronger, measured in watts, than those to which an ordinary telephone receiver responds. Whereas less than six tenmillionths of an ampere are sufficient to produce a response from an ordinary telephone receiver, a current of an ampere is sometimes used in the Cahill system for an instant when loud tones are produced.

The composition or quality of a note or chord is controlled by eight rheostats called stops. By skillful manipulation of the stop rheostats, it is possible to obtain very accurate imitations of the wood-winds and several other orchestral instruments. Imitation, however, is hardly the right word ; for the notes are built up of exactly the same components as the tones which come from the reaJ instruments. Furthermore, beautiful effects are obtained that cannot be produced on any existing instrument. These stop rheostats control merely the timbre or quality of the music produced. Fluctuations in volume are produced by “expression rheostats.” Both stop and expression rheostats are constituted by impedance coils, differing however in mechanical construction. The stop rheostats are manipulated very much like the stops of an organ, and the expression rheostats like the swell. Unlike an organ swell, however, the expression rheostats are used not only for producing captivating crescendos and diminuendos of individual notes and chords, but also in reproducing the peculiar singing tremolo of the violin and ‘cello.

The rather complex system of transformers described serves not merely to blend partials with ground tones, but also to purify the vibrations corresponding with the different sets of partials by purging them of their harsher components. The air core transformers, fur thermore, permit the selection of voltages according to the resistance which the final current will encounter. Inasmuch as each keyboard controls ground-tone and overtone mixing devices, it is possible to produce notes of the same timbre or of different timbres. Excellent orchestral effects can, therefore, be obtained by causing the one keyboard to sound wind instruments, such as oboes, flutes, clarinets, or horns, and the other to sound the tones of the violin or other stringed instruments.

From this necessarily cursory consideration of the telharmonium, it is evident that the music is initiated as electrical vibrations, distributed in the form of electricity, and finally converted into aerial vibrations at a thousand different places separated hundreds of miles, it may be. No musical instruments in the sense in which we understand the word are used. Not a string, reed, or pipe is anywhere to be found. The vibrations produced by the performers’ playing are wholly electrical, and not until they reach the telephone receiver can they be heard. The telephone reo ceiver acts for us as a kind of electrical ear to hear oscillations to which our own ears are insensitive. When Mark Twain heard the telharmonium, he fancifully suggested that the military parade’ of the future would be a more beautifully rhythmic procession than our present pageants. The usual military bands heading the various regiments and playing marches, not in unison, although the same in time, will give place to musical arcs disposed along the line of march, all crashing out their stntins in perfect time. The soldiers who will march in that future parade win all hear the blare of invisible electrical trumpets and horns at the same moment; they will all raise their left feet at exactly the same instant, just as if they were but one company.

So far as the capabilities of the telharmonium are concerned, it may be stated that the New York installation is able to supply ten thousan-d subscribers, or more, with music of moderate volume at widely remote places. The very remarkable and rapid development of the invention has been thus eloquently set forth by Prof. A. S. McAllister in an article published in the Electrical World :

“From Hero, who first proposed to utilize the motive power of steam, to Watt’s first successful engine, was almost two thousand years. And between the proposal of Hero and the accGmplishment of Watt many inventors in different countries made ineffective attempts to attain the goal desired. From Huyghens’s proposal of an explosive motor to Otto’s successful machine two centuries elapsed, with scores of patents in the different countries of Europe. So from Sir Humphry Davy’s experimental arc to the Brush and Edison arc lighting machines” three-quarters of a century elapsed, during which scores of inventors in different countries endeavored to solve the problem in vain. Similar remarks apply to the progress of most great inventions, electri· cal and mechanical. But the process of producing music from dynamos has been carried from the first conception to the successful working machine by one man-Thaddeus Cahill-in a few years. And when one hears the plant at Thirty-ninth Street and Broadway, with its musical tones already equaling, if not surpassing, the instruments of the orchestra, one wonders what cannot be expected in a few years to come when the inventor will have had time to do his best, and when his work in all its details will be known ·to the world and open to improvement by others, and when musicians will have learned to use the new powers which electricity is placing at their command. Clearly the world has, through the wonderful powers of the electrical forces and the skillful use made of them by Dr. Cahill, a new music, a music which can be produced in many thousand places simultaneously, and which in its very infancy seems destined to surpass in sympathy and responsiveness-in artistic worth-the existing music of pipe and string, the evolution of many centuries.”

From ‘Scientific American’ vol 96 #10 9th March 1907

The end of the Telharmonium

The reason for the failure of Cahill’s project were numerous. The machine itself was impossibly expensive; about $1 million was spent from 1897 to 1914 on the project ( approximately $30 million in today’s value) and it was unlikely that a subscriber business model would have ever covered the costs, let alone make a profit – and, even if Cahill had found enough subscribers, he’d have to have built a power plant to generate enough power.

The output power of the Telharmonium caused great disruption of the New York Telephone network, angering telephone subscribers and even interrupting the Stock Exchange, which resulted eventually in AT&T refusing to co-operate in supporting Cahill’s instrument.

The Telharmonium was also a victim of an age of rapid technical advances; Lee De Forest began experimenting with radio transmissions as early as 1906 (which included transmissions of the Telharmonium) and by around 1914 wireless radio broadcasts had spelled the end for wire broadcasting.

The technology developed by Cahill did however continue. In 1934 the American watchmaker Laurens Hammond developed a new electronic home organ which was essentially a miniaturised Telharmonium

“Thaddeus Cahill, developer of the Telharmonium, was . . . endowed with the ability to think big. Although not strictly electronic (it predated the invention of the vacuum tube by about a decade), the Telharmonium embodied many basic principles that have been used in the electronic music medium: the generation of pitched tones from alternating electricity, the addition of harmonics to determine tone color (additive synthe- sis), and a touch sensitive keyboard to shape the sounds and control their strengths. This first polyphonic, touch sensitive music synthesizer remained in service in New York for only a few years . . . The basic idea was resurrected again in the 1930s in an instrument that was somewhat more of a commercial success: the Hammond Organ.”

Robert A. Moog,”ElectronicMusic,”Journal of the Audio Engineering Society, October/November 1977, 25:10/11, 856.

Baker’s article on the Telharmonium for McClure’s Magazine, ‘New Music for an Old World,’ came to the attention of the Italian virtuoso classical pianist and critical intellectual Ferruccio Busoni who enthused about the instrument in his 1907 ‘Sketch of a New Aesthetic of Music’ which proposed a new music constructed of infinite gradations of tone, surpassing the 12 note scale and traditional orchestration:

“The question is important and imperious, how and on what are these tones are to be produced. Fortunately, while busied with this essay, I received from American direct and authentic intelligence which solves the problem in a simple manner. I refer to an invention by Dr. Thaddeus Cahill. He has constructed a comprehensive apparatus which makes it possible to transform an electric current into fixed and mathematically exact number of variations.”

and, directly inspired by Cahill’s instrument– though he never actually heard it:

 “Who has not dreamt that he could not float on air? And firmly believed his dream to be reality? Let us take thought, how music may be restored to its primitive, natural essence; let us free it from archectonic, acoustic and aesthetic dogmas; let it be pure invention and sentiment, in harmonies, in forms, in tone-colours (for invention and sentiment are not the prerogative of melody alone); let it follow the line of the rainbow and vie with the clouds in breaking sunbeams; let Music be naught else than Nature mirrored by and reflected from the human breast; for it is sounding air and floats above and beyond the air; within Man himself as universally and absolutely as in Creation entire…”

Busoni’s manifesto of 1907 inspired his students including a young Edgard Varèse as well as a whole new school of microtonal instrument designers and musicians. Varèse on arriving at New York in 1915 went to see the instrument in it’s final days and was not much impressed:

“[Busoni] was very much interested in the electrical instruments we began to hear about and I remember particularly one he had read of in an American magazine, called the Dynamophone, invented by a Dr. Thaddeus Cahill, which I later saw demonstrated in New York and was disappointed.”

Louise Varèse, Varèse: A Looking-Glass Diary, Vol. I, New York: W.W. Norton and Company, 1972, 50;

Inside the Telharmonium:

Mark Twain (Clemens) remembers the Telharmonium:

“I recall two pleasant social events of that winter: one a little party given at the Clemenses’ home on New-Year’s Eve, with charades and storytelling and music. It was the music feature of this party that was distinctive; it was supplied by wire through an invention known as the telharmonium which, it was believed, would revolutionise musical entertainment in such places as hotels, and to some extent in private houses. The music came over the regular telephone wire, and was delivered through a series of horns or megaphones — similar to those used for phonographs — the playing being done, meanwhile, by skilled performers at the central station. Just why the telharmonium has not made good its promises of popularity I do not know. Clemens was filled with enthusiasm over the idea. He made a speech a little before midnight, in which he told how he had generally been enthusiastic about inventions which had turned out more or less well in about equal proportions. He did not dwell on the failures, but he told how he had been the first to use a typewriter for manuscript work; how he had been one of the earliest users of the fountain- pen; how he had installed the first telephone ever used in a private house, and how the audience now would have a demonstration of the first telharmonium music so employed. It was just about the stroke of midnight when he finished, and a moment later the horns began to play chimes and “Auld Lang Syne” and “America”.”Mark Twain: A Biography,Albert Bigelow Paine (New York: Harper & Brothers, 1912), 1364-1365

Patent Documents


‘MAGIC MUSIC FROM THE TELHARMONIUM’ Reynold Weidenaar Scarecrow Press 800/642-6420; 301/459-3366
Holmes, Thomas B. Electronic and Experimental Music. New York: Scribner, 1985. pp. 32-41
‘Scientific American’ vol 96 #10 9th March 1907
‘ New Music for an Old World’ McClure’s magazine. v.27 1906 May-Oct.
“The Telharmonium: A History of the First Music Synthesizer,” review by Thomas L Rhea. Computer Music Journal, vol. 12 #3, 1988
Gunter’s Magazine [v5 #5, June 1907] The Home Publishing Company, 503-622pp