|Rock Music is a genre of popular music that developed during and after the 1960s, particularly in the United Kingdom and the United States. It has its roots in 1940s and 1950s rock and roll, itself heavily influenced by rhythm and blues and country music. Rock music also drew strongly on a number of other genres such as blues and folk, and incorporated influences from jazz, classical and other musical sources.
Musically, rock has centred around the electric guitar, usually as part of a rock group with bass guitar and drums. Typically, rock is song-based music with a 4/4 beat utilizing a verse-chorus form, but the genre has become extremely diverse and common musical characteristics are difficult to define. Like pop music, lyrics often stress romantic love but also address a wide variety of other themes that are frequently social or political in emphasis.