On December 24, 1906, in a wooden shack crammed with equipment in the seaside Massachusetts community of Brant Rock, a 40-year-old inventor named Reginald Fessenden made the world’s first radio broadcast. The program consisted of a phonograph recording of a Handel piece followed by Fessenden playing “O, Holy Night” on the violin, reading from the Bible, and wishing his listeners (mostly crewmen on United Fruit Company ships, which had been equipped with his apparatus) a merry Christmas. This broadcast and a second one on New Year’s Day were heard as far away as the West Indies. In fact, in November, a test transmission had been picked up in Scotland.

Fessenden, a Quebec native, had been a schoolmaster in Bermuda, an assistant in Thomas Edison’s laboratory, an electric-company engineer, a college professor, and a communications researcher for the U.S. Weather Bureau. In the last of these positions, he was assigned to develop a wireless system to transmit forecasts and data. The Weather Bureau had a telegraph in mind, but Fessenden thought he could transmit voice as well. When results were promising, he resigned to form his own company.

His greatest breakthrough was the “heterodyne” principle, which is still in use today. In this method, he transmitted a signal at very high frequencies, around 50,000 cycles per second. The transmitted signal was varied slightly, up and down, by mixing it with a lower-frequency voice signal. At the receiving end, the voice portion of the signal could be extracted. The use of high frequencies was the key; it greatly reduced interference and allowed the use of smaller antennas. Basically, Fessenden’s system let low-frequency voice signals be broadcast at high frequencies.

Unfortunately, the holiday broadcasts turned out to be the high point of Fessenden’s radio career. His company ran into financial troubles, he squabbled with his backers, and as for their main goal — establishing reliable wireless transatlantic telegraph service — Guglielmo Marconi beat them to the punch a few months later. Fessenden got out of the radio business in 1911 and from then on concentrated on marine communication, military technology, and even a primitive form of television. He died in 1932.

For good or ill, Fessenden’s pioneering broadcast showed the way for the talk shows and shock jocks of today. From a technological standpoint, however, it was a dead end. In essence, Fessenden was sending voice signals over souped-up telegraph equipment. It worked, but it required expensive and finicky apparatus, a trained operator, and favorable weather conditions. Another breakthrough, Lee de Forest’s Audion vacuum tube, would be needed to make radio a consumer product. Even then the technology did not become widespread until the mid-1920s, two decades after Fessenden’s brilliant failure.