1. [n]  a genre of popular music originating in the 1950s; a blend of Black rhythm-and-blues with White country-and-western; "rock is a generic term for the range of styles that evolved out of rock'n'roll."
2. [n]  a genre of popular music originating in the 1950s; a blend of Black rhythm-and-blues with White country-and-western; "rock is a generic term for the range of styles that evolved out of rock'n'roll."

Rock and Roll
A study of the origins and history of rock music discusses the major performers and musicians, their innovations in instrumentation and musical style, and the impact of rock music on modern culture

more details ...