Hip hop began as a form of expression for black Americans living in urban areas, but today has spread throughout the world. The genre has changed greatly throughout the years. Rappers, emcees, and disc jockeys create the music, but hip hop also encompasses other disciplines, such as dance and art. Today, hip hop is popular with people of all ages and backgrounds, both in the United States and internationally. People listen to it in their homes and dance to it in the clubs. This popularity means that hip hop has had a strong influence on everyday life, affecting everything from fashion to television shows and political campaigns. The Evolution & Cultural Influences of Music series examines the history and development of popular musical genres. Books in this series provide young readers with a greater understanding of each musical genre, and how it has contributed to and shaped American popular culture over the past half-century.