Details: This poster shows four pictures of girls making music. It shows one girl singing into a microphone, and three other girls playing different types of guitars. At the bottom it says "Girls Rock!"
Rock music is a genre of popular music that entered the mainstream in the 1960s. It has its roots in 1940s and 1950s rock and roll, rhythm and blues, country music and also drew on folk music, jazz and classical music. The sound of rock often revolves around the guitar back beat laid down by a rhythm section of electric bass guitar, drums, and keyboard instruments such as organ, piano, or, since the 1970s, synthesizers. A group of musicians specializing in rock music is called a rock band or rock group. A girl is any female human from birth through childhood and adolescence to attainment of adulthood. The term may also be used to mean a young woman.