From the 1940s through the early 1960s, a new form of popular music was born in the United States-one that would take the world by storm. Detroit disc jockey Alan Freed, among the very first to play and promote new music, christened it "Rock 'n Roll" from an old blues lyric. Detroit, like New York, Philadelphia, Chicago, Los Angeles, and Memphis, contributed its own distinctive regional character to the music and became a hub of industry activity...