The earliest purely electronic musical instrument was the Telharmonium or Teleharmonium, developed by Thaddeus Cahill in 1897. The Telharmonium was intended to be listened to using telephone receivers.

Like the later Hammond organ, the Telharmonium used electromechanical tonewheels to generate musical sounds as electrical signals by additive synthesis. An authoritative history of the Telharmonium is 'Magical Music from the Telharmonium' by Reynold Weidenaar, Scarecrow Press, 1995.

The Mark I version weighed 7 tons. The Mark II version weighed almost 200 tons. Cahill built three versions in total, each one being a considerable advancement over the features of its predecessor. A small number of performances in front of a live audience were given in addition to the telephone transmissions. Performances in New York were well received by the public in 1906, and the performer would sit at a console (see picture) to control the instrument. The actual mechanism of the instrument itself was so large it occupied an entire room — wires from the controlling console were fed discreetly through holes in the floor of an auditorium into the instrument room itself, which was housed in the basement beneath the concert hall.

The Telharmonium foreshadowed modern electronic musical equipment in a number of ways. For instance, its sound output came in the form of connecting ordinary telephone receivers to large paper cones — a primitive form of loudspeaker. Indeed, Cahill was noted for saying that ideally, electromagnetic diaphrams were the most preferable means of outputting its distinctive sound.

Although no recordings exist of the Telharmonium, observers reported that its sound was very clear and pure — probably referring to the sine tones it was capable of producing. However, it was not restricted to such simple sounds. Each tonewheel of the instrument corresponded to a single note, and, to broaden its possibilities, Cahill added several extra tonewheels to add harmonics to each note. This, combined with organ-like stops and multiple keyboards (the Telharmonium was polyphonic), as well as a number of foot pedals, meant that every sound could be sculpted and reshaped — the instrument was noted for its ability to reproduce common orchestral woodwind instruments such as the flute, bassoon, clarinet, and also the cello.

The Telharmonium's demise came for a number of reasons. Its immense size, weight and power consumption (this being in an age before vacuum tubes had been invented) caused obvious problems. In addition, problems began to arise when telephone broadcasts of Telharmonium music were subject to crosstalk and unsuspecting telephone users would be interrupted by strange electronic music. By 1912, interest in this revolutionary instrument had worn off, and Cahill's company was later declared bankrupt.

External links

• http://www.synthmuseum.com/magazine/0102jw.html
• http://csunix1.lvc.edu/~snyder/em/dyna.html