Rhythm and blues, frequently abbreviated as R&B or R'n'B, is a genre of popular music that originated within African American communities in the 1940s. The term was originally used by record companies to describe recordings marketed predominantly to African Americans, at a time when "rocking, jazz based music ... [with a] heavy, insistent beat" was starting to become more popular. In the commercial rhythm and blues music typical of the 1950s through the 1970s, the bands usually consisted of a piano, one or two guitars, bass, drums, one or more saxophones, and sometimes background vocalists. R&B lyrical themes often encapsulate the African-American history and experience of pain and the quest for freedom and joy, as well as triumphs and failures in terms of societal racism, oppression, relationships, economics, and aspirations.