a type of pop music originating in the 1950s as a blend of rhythm and blues and country and western. It is generally based upon the twelve-bar blues, the first and third beats in each bar being heavily accented
(as modifier) the rock-and-roll era
dancing performed to such music, with exaggerated body movements stressing the beat
also rock 'n' roll, 1954 in reference to a specific style of popular music, from rock (v.2) + roll (v.). The verbal phrase had been a Black English euphemism for "sexual intercourse," used in popular dance music lyrics and song titles since at least the 1930s.