One of the first synthesizers that used electricity to generate and transmit sounds. Invented by Elisha Gray in 1876. (And here we must digress. Elisha Gray also “invented” the telephone, in 1874, but arrived at the U.S. Patent Office a scant three hours after Alexander Graham Bell did, and thus lost out on the glory. After years of lawsuits, Gray’s company, Western Electric, became the sole-source manufacturer of telephones, while Bell’s company controlled the transmission lines.)
Gray accidentally discovered that he could control sound from a self-vibrating electromagnetic circuit and in doing so invented a basic single-note oscillator. The Musical Telegraph used steel reeds whose oscillations were created and transmitted over a telephone line, by electromagnets. It contained enough single-tone oscillators to play two octaves and later models were equipped with a simple tone wheel control. Gray also built a simple loudspeaker device in later models consisting of a vibrating diaphragm in a magnetic field to make the oscillator audible.