Rock and roll

Rock and roll is a genre of popular music that evolved in the United States during the late 1940s and early 1950s. The origins of rock and roll are rooted in a blending of black musical genres, mainly rhythm and blues, with stylistics influences from gospel, jazz, boogie-woogie, electric blues, jump blues, swing, and folk music. While rock and roll's early elements can be heard in blues records from the 1920s and in country records of the 1930s, the genre did not acquire its name until 1954.

By the mid-1960s, rock and roll had developed into "the more encompassing international style known as rock music, though the latter also continued to be known in many circles as rock and roll". For the purpose of differentiation, this article deals with the first definition.

In the earliest rock and roll styles, either the piano or saxophone was typically the lead instrument. These instruments were generally replaced or supplemented by the electric guitar in the mid-to-late 1950s. The beat is essentially a dance rhythm with an accentuated backbeat, almost always provided by a snare drum. Minimal blues chord progressions such as the twelve-bar blues are commonly used. Classic rock and roll is usually played with one or more electric guitars (one lead, one rhythm) and a double bass (string bass). After the mid-1950s, electric bass guitars (first mass-produced by Fender in the early 1950s) and drum kits became popular in classic rock.

Rock and roll had a profound influence on contemporary American lifestyles, fashion, attitudes, and language, and is often portrayed in movies, fan magazines, and on television. According to G. C Altschuler the music had a positive influence on the civil rights movement, because of its widespread appeal to both Black American and White American teenagers.