Rock and Roll is a genre of music that evolved in the United States in the late 1940s and early 1950s, and quickly spread to the rest of the world. Classic rock and roll is played with one or two electric guitars, a string bass or an electric bass guitar, and a drum kit. 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 unprecedented 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 later spawned the various sub-genres of what is now called simply rock music.