<P> The next advancement was the vacuum tube detector, invented by Westinghouse engineers . On Christmas Eve 1906, Reginald Fessenden used a synchronous rotary - spark transmitter for the first radio program broadcast, from Ocean Bluff - Brant Rock, Massachusetts . Ships at sea heard a broadcast that included Fessenden playing O Holy Night on the violin and reading a passage from the Bible . This was, for all intents and purposes, the first transmission of what is now known as amplitude modulation or AM radio . </P> <P> In June 1912 Marconi opened the world's first purpose - built radio factory at New Street Works in Chelmsford, England . </P> <P> The first radio news program was broadcast August 31, 1920 by station 8MK in Detroit, Michigan, which survives today as all - news format station WWJ under ownership of the CBS network . The first college radio station began broadcasting on October 14, 1920 from Union College, Schenectady, New York under the personal call letters of Wendell King, an African - American student at the school . </P> <P> That month 2ADD (renamed WRUC in 1947), aired what is believed to be the first public entertainment broadcast in the United States, a series of Thursday night concerts initially heard within a 100 - mile (160 km) radius and later for a 1,000 - mile (1,600 km) radius . In November 1920, it aired the first broadcast of a sporting event . At 9 pm on August 27, 1920, Sociedad Radio Argentina aired a live performance of Richard Wagner's opera Parsifal from the Coliseo Theater in downtown Buenos Aires . Only about twenty homes in the city had receivers to tune in this radio program . Meanwhile, regular entertainment broadcasts commenced in 1922 from the Marconi Research Centre at Writtle, England . </P>

Who made radio possible to the masses in 1920