Rockabilly had its roots in country, blues, folk, hillbilly, R&B, boogie-woogie and most other indigenous Deep South forms of popular song that you could strum three chords along to or howl down a cheap microphone. It was young people's music, made almost entirely by the first wave of teenagers, despised by adults in general and the country music establishment in particular. Its pioneer exponent, Elvis, eventually become respectable in the eyes of...