The streets of London began humming in 1878. Where once had stood streetlights powered by pipelines of flammable coal gas now were the first "electric candles," primitive lamps that produced light as intense electric arcs between two electrodes. They were uncomfortably bright and harsh compared to the incandescent lightbulbs that would soon enough replace them—in the US they were often housed atop very tall "moonlight towers"—but the arc lamps had another undesirable side effect: noise.
Arc lights produce a continuous, loud sound as current sparks wildly from electrode to electrode. A melange of humming, hissing, and howling, the result is more or less like what you might imagine raw electricity to sound like:
In 1899, an English physicist named William Duddell, a thinker already responsible for several inventions of early-days electrical engineering, set about trying to solve the arc lamp noise problem, to no avail. Instead, he ended up inventing the first fully electric musical instrument, which was described in a report published in Nature on Dec. 20, 1900. Other instruments had by then used electricity, but Duddell offered an instrument that was electricity. According to Nature, the result "excelled in beauty."
It had been noted prior to Duddell's work that changing the voltage of an arc lamp changed the pitch of its hum, but he took it a step further and hooked one up to a makeshift keyboard. He could not only modulate pitches, but reproduce proper musical notes. The invention was dubbed the "singing arc."
The singing arc had a peculiar side effect. As Duddell modulated the voltage of one with his keyboard, other nearby arc lamps also responded, with the result being a sympathetic electric choir.
This was an inadvertent discovery. As Duddell presented his findings, and his new instrument, at the London Institution of Electrical Engineers, two nearby laboratories were at that very moment engaged in their own research on electrical arcs. As Duddell demonstrated his keyboard, arcs being observed in the nearby labs began singing in concert. At the time, this sudden emergence of musical behavior was unexplainable.
The dawn of Musak would thus be found in the hiss of poorly tamed electricity.
"All three arcs were found to be supplied with current from the street mains, and it was clear that this main current had been varied in such a way by Mr. Duddell's keyboard as to reproduce in the two other laboratories the tunes which he supposed he was playing only to his audience in the lecture room," the New York Times later reported. "This obviously meant that by playing on one properly arranged keyboard tunes could be reproduced in a number of different arcs and at a distance from the musician."
The Times went on to suggest "the use of the arc light for public entertainment," a new distributed musical instrument that could be employed in train stations, on city streets, and in public halls. Public utilities would offer whole concerts packaged in with electrical service. The dawn of Musak would thus be found in the hiss of poorly tamed electricity.
"The possible applications of such a musical instrument are obviously very numerous, and if it proves a practical contrivance and is reasonably harmonious, it will surely find many novel uses," the Times gushed. "A musical house-to-house service, on the same plan as the telephonic newspaper, which is said to be very popular and successful in Budapest at present, is one of these."
Streetlight Spotify never really came to pass, but what Duddell had really built was one of the first electronic oscillators. His was limited to audio frequencies, but it didn't take long before engineers had modified it to radio frequencies. In 1902, the Danish physicist Valdemar Poulsen produced a generator that produced oscillations in the megahertz range, and, by 1907, these waves were being used in wireless telegraphs and telephones.
It was Poulsen that wound up patenting the arc generator, but Duddell retains the credit for basically predicting an entire new universe of music.