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The Telharmonium:

An Early Breakthrough in Electronic Music


Anyone who has navigated through the Internet very often is undoubtedly aware of live events -- concerts, performances, lectures -- being transmitted via World Wide Web from time to time. Similarly, flipping through the concert listings in a local publication (such as the Austin Chronicle) will occasionally reveal that a given concert in town is scheduled to be broadcast over the Internet. Performances such as these have a direct antecedent in an ambitious, groundbreaking experiment in electronic music: inventor Thaddeus Cahill's telharmonium.

Thaddeus Cahill (1867-1934) first patented his telharmonium a century ago in 1896, when he described the instrument as a large system capable of electrically generating, controlling, and shaping sounds, which could be reproduced through a loudspeaker system. The instrument itself was a direct precursor to the modern synthesizer -- Cahill, in fact, used the term "synthesizing" in his patent to describe the device's operation -- yet the debut of the transistor, essential to the modern synthesizer's development, was still half a century away. The theremin, another very early experiment in electronic music, itself did not appear until ca. 1920.

The telharmonium generated its sounds using a system of alternators called "rheotomes." Each rheotome was actually a cog with a specific number of notched teeth. As the edge of the rheotome rotated against a wire brush (part of a larger circuit), the teeth would contact the brush a certain number of times each second, based on the rheotome's diameter. This resulted in the electrical oscillation of a sonic frequency. Several rheotomes -- one to generate a fundamental frequency along with several more to "flesh out" the sound with harmonic overtones -- would be arranged on one rotating "pitch shaft," with one shaft corresponding to one note of the chromatic scale (and controlled by one key on a piano-style keyboard). Although the patent called for a total of 408 rheotomes, Cahill eventually devised a more efficient method in which the same rheotome would produce the fundamental frequency for one note, or a harmonic overtone for another (and vice-versa). The same mechanism was employed with far greater success in the Hammond organ a few decades later.

The telharmonium keyboard was touch-sensitive, just like that of a piano (it has taken until the last 15 years or so for the same feature to be incorporated into the modern synthesizer). The console allowed the sounds to be mixed and filtered to emulate the various brass, woodwind, and string instruments heard in orchestras.

Cahill built the first telharmonium as a demonstration model in 1900. In 1902, in an effort to secure financial backing from fellow Washingtonian George Westinghouse, Cahill sent telharmonium music over a telephone line to Westinghouse's home. This reflected Cahill's larger plan to link his instruments to homes, hotels, restaurants, and offices, each of whom would purchase subscriptions for this service. The concept predates the commercial broadcasting of music via radio, but more directly prefigures developments such as Muzak systems, cable television, and the Internet. In fact, following the telegraph, Cahill's invention may represent the first use of telephone lines to transmit any type of information other than normal human speech; more specifically, the telharmonium may be considered the first in a series of efforts to transmit a live musical performance via communication lines, thus making Internet broadcasts merely the most recent example of this.

Cahill never succeeded in building a telharmonium to the exact specifications set forth in his patent, but in 1906, he did complete a second model in Holyoke, Massachusetts. On March 16 of that year, musician Edwin Hall Pierce gave several telharmonium performances which were transmitted one mile via telephone from Cahill's factory to the ballroom of the Hotel Hamilton, where a telephone receiver had been equipped with a large paper horn (although Cahill's patent called for the inclusion of electromagnetic loudspeakers, they were apparently never built). This telharmonium employed 145 rheotomes, was 30 feet in length, employed nearly two thousand switches, and weighed 200 tons.

Despite the instrument's immense size, the entire system was transported (on 30 flatcars) to New York City. There, the New York Electric Music Company planned to hold live telharmonium concerts which, in accordance with Cahill's plans, would be transmitted to subscribers over telephone lines. Although a number of subscribers were found, complaints arose concerning the telharmonium's interference with other telephone traffic. Combined with the fact that then-current technology was too inadequate for Cahill's vision, this ultimately led to operations ceasing.

Depending on one's view, the telharmonium became either nothing more or nothing less than one of the most important footnotes in the history of electronic music and telecommunications.


Holmes, Thomas B. Electronic and Experimental Music. New York: Scribner, 1985. pp. 32-41