Belleville (Illinois) News Democrat, December 13, 1919, page 6:

Wireless  Sends  Jazz  600  Miles  Through  Space

    Chicago, Ill,. Dec. 13 -- Amateur wireless "bugs" in the middle west were entertained yesterday afternoon by jazz music and grand opera, thrown out from the United States navy station on the Transportation building. With a high power telephone transmitter and a phonograph, Chief Electrician Grover M. Dickman, U. S.  N., performed the test.
    A record entitled "I've Got My Captain Working For Me Now" was placed on the machine, the transmitter of the wireless telephone being placed in the sound chamber.
    The Great Lakes Naval station operator on duty heard it. "Great!" he applauded by radio. An amateur in Mount Pleasant, Ia., radioed his appreciation and from government stations throughout the districts within a radius of 600 miles came flashes meaning "Ha! Ha!"