The document provides an overview of different genres of popular music including rock n' roll, disco, and pop music. It discusses the origins and characteristics of each genre. Rock n' roll developed from the 1940s-1960s combining blues, jazz, and other styles and typically featured guitars, bass, and drums. Disco emerged in the 1970s as a dance-focused form of rock featuring soulful rhythms from strings, horns, and keyboards. Pop music originated in the mid-1950s in the US and UK and encompasses many commercial styles, though it is often synonymous with rock except from the late 1960s onward. Today's pop features diverse artists from music groups to K-pop bands.