Originally Posted by Wikipedia

Rockabilly is one of the earliest styles of rock and roll music, dating to the early 1950s.

The term rockabilly is a portmanteau of rock (from rock 'n' roll) and hillbilly, the latter a reference to the country music (often called hillbilly music in the 1940s and 1950s) that contributed strongly to the style's development. Other important influences on rockabilly include western swing, boogie woogie, and rhythm and blues. While there are notable exceptions, its origins lie primarily in the Southern United States.

The influence and popularity of the style waned in the 1960s, but during the late 1970s and early 1980s, rockabilly enjoyed a major revival of popularity that has endured to the present, often within a rockabilly subculture.

Originally Posted by Rate Your Music

Rockabilly started in the mid-50s at the dawn of Rock & Roll with the influential recordings Elvis Presley made for Sun Records. Originally it was Country musicians playing their own version of uptempo Rhythm & Blues music, resulting in this new style. It usually features driving guitars, frantic vocals and slap-back echo in the bass. Rockabilly still has a big following with new artists emerging every year.