Rock and roll (also known as rock 'n' roll) is a form of music that evolved in the United States in the late 1940s and early 1950s, with roots in mostly African American music genres, and quickly spread to the rest of the world.

Classic rock and roll is played with one or two electric guitars (one lead, one rhythm), a string bass or (after the mid-1950s) an electric bass guitar, and a drum kit. In the earliest rock and roll styles of the late 1940s and early 1950s, either the piano or saxophone was often the lead instrument, but these were generally replaced or supplemented by guitar in the middle to late 1950s. The beat is essentially a boogie woogie blues rhythm with an accentuated backbeat, the latter almost always provided by a snare drum.

The massive popularity and eventual worldwide view of rock and roll gave it an unique social impact. Far beyond simply a musical style, rock and roll, as seen in movies and in the new medium of television, influenced lifestyles, fashion, attitudes, and language. It went on to spawn various sub-genres, often without the characteristic backbeat, that are more properly called simply 'rock music'.