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. Its roots lay mainly in rhythm and blues, country, folk, gospel, and jazz. The style quickly spread to the rest of the world and developed further, leading ultimately to modern rock music.

The term "rock and roll" now covers at least two different meanings, both in common usage. The American Heritage Dictionary and the Merriam-Webster Dictionary both define rock and roll as synonymous with rock music. Conversely, Allwords.com defines the term to refer specifically to the music of the 1950s.