Popular Mechanics, August, 1919, page 251:
WIRELESS MUSIC ENTERTAINS MEN ON SHIPS AT SEA
Like all well-regulated ships, the transport "George Washington" has a phonograph. It also has wireless-telephone equipment of the latest design. On a recent occasion the phonograph horn and the telephone transmitter were brought face-to-face, and the music started. A hundred miles away, soldiers and sailors on the transport "President Grant" gathered eagerly around a loud-speaking receiver, from which issued the merry strains of song and fox trot, as the concert ship threw its melodious vibrations into space. Within the hundred-mile radius were several other radio-equipped ships, and when the concert was over the "George Washington's" operator was kept busy receiving encores.