Rock music of Canada the 1920s, rock and roll did not acquire its name until the 1950s. "Rock"' or its forerunners electric blues (Chicago blues) and rhythm and blues (Jump blues) was first heard in the late 1940s by Canadians who were living close enough to the American border to tune into American radio station broadcasts. In 1951, Cleveland, Ohio, disc jockey Alan Freed began playing rhythm and blues music for a multi-racial audience, and is credited with first using the phrase "rock and roll" to describe the musical sound of the Doo-wop vocal groups and the rockabilly singers who emerged in the 1950s.
Origins of rock and roll "Moondog" for himself and any concerts or promotions he put on because he used as his regular theme music a piece called "Moondog Symphony" by the street musician Louis "Moondog" Hardin. Hardin subsequently sued Freed on grounds that he was stealing his name, and because Freed was no longer allowed to use the term Moondog, he needed a new catchphrase. After a night of heavy drinking, he and his friends came up with the name "The Rock and Roll Party" because he already was using the phrase "Rock and Roll Session" to describe the music he was playing. As his