Rock music is a genre of popular music that originated as "rock and roll" in the United States in the early 1950s, and developed into a range of different styles in the 1960s and later, particularly in the United Kingdom and the United States.
Typically, rock is song-based music usually with a 4/4 time signature using a verse–chorus form, but the genre has become extremely diverse. Like pop music, lyrics often stress romantic love but also address a wide variety of other themes that are frequently social or political.