This broadcast referred to in this article took place on February 22, 1917 -- the 185th birthday of George Washington, first President of the United States.
The Electrical Experimenter, August, 1917, page 255:

Tina  Lerner's  Playing  on  Board  Ship  Heard  on  Other  Vessels  500  Miles  Away
    Imagine sailing on a ship in mid-ocean and being able to hear your favorite pianist in a concert that she is giving on board a vessel hundreds of miles away! The possibility is not so remote as one might surmise, for on Washington's birthday last, Tina Lerner, the distinguished young Russian pianist, gave a recital on board the Ventura on her homeward journey from Honolulu, and enjoyed the unique thrill of feeling that her music was being heard by wireless, operators on board passenger and freight steamers as far as 500 miles away.
    In the concert room where Miss Lerner was playing, a transmitter was placed, and by means of a recently perfected wireless telephone apparatus, the music was sent out over a large radius.
    The experience of listening to this concert was far more novel than participating in the demonstrations which have recently been tried successfully, when singers and speakers in San Francisco were heard at meetings and banquets in New York and other cities. At these functions the guests were provided with telephones thru which they heard every tone distinctly. Even the applause that the singers received on the Pacific Coast was accurately transmitted, and all the thrills that attended the real concert were felt by this "proxy audience" on the other side of the continent. That, however, was over telephone wires. To play the piano while isolated in mid-ocean and have the notes float thru the air and bring pleasure to those far distant, does much toward the complete annihilation of space and causes us to wonder what tomorrow may bring forth.
    When we are far from home--and think of the loved ones left behind, shall we be able to commune with them thru music?