Aberdeen (South Dakota) American, December 12, 1919, page 1:
Jazz Concert and Grand Opera Over Wireless
Chicago, Dec. 11--Amateur wireless operators in many cities were entertained tonight by jazz music and grand opera thrown out from the United States navy station.
A high power telephone transmitter and a phonograph were used by chief electrician Grover M. Dickman. Operators at Great Lakes, Milwaukee, Mount Pleasant, Iowa and other cities within 300 miles of Chicago by radio acknowledged appreciation of the concert.
Regular concerts are planned by Chief Dickman who said the music was very clear.