While Guglielmo Marconi was transmitting the dots and dashes of Morse code, another scientist, Canadian Reginald Fesseden, was pursuing a loftier goal. Fessenden aimed to transmit the human voice and music-without wires.

As head of the electrical engineering department at the University of Pittsburgh, Fessenden developed a way of sending Morse code more effectively then Marconi was doing. Fesseden devised the theory of the "continuous wave," a means to superimpose sound onto a radio wave and transmit this signal to a receiver. After years of experimentation, on December 23, 1900, he successfully transmitted the sound of a human voice between two 50-foot towers.

But Fesseden still had to fight to prove his theory. After struggling to obtain financial backing for further experiments, Fessenden beamed the first long-range transmissions of voice on Christmas Eve, 1906, from a station in Massachusetts. This first radio program featured the inventor playing "O Holy Night" on his violin, then singing carols with his wife and a friend. Hundreds of miles out in the Atlantic, astonished ship radio operators heard the Christmas music.

Remarkable though his accomplishment was, Fessenden never achieved the fame of Marconi and others. And although Fessenden's work made voice radio possible, it took another 10 years before it became commonplace.