On a Saturday night in 1948, Hank Williams stepped onto the stage of the Louisiana Hayride and sang "Lovesick Blues." Up to that point, Williams's yodeling style had been pigeon-holed as hillbilly music, cutting him off from the mainstream of popular music. Taking a chance on this untried artist, the Hayride--a radio "barn dance" or country music variety show like the Grand Ole Opry--not only launched Williams's career, but went on to launch the careers of well-known performers such as Jim Reeves, Webb Pierce, Kitty Wells, Johnny Cash, and Slim Whitman.

Broadcast from Shreveport,...