Rhythm and blues is a term describing popular African American music that originated in the 1940s. The term was originally used by record companies to describe recordings marketed predominantly to urban African Americans, at a time when "urbane, rocking, jazz based music with a heavy, insistent beat" was becoming more popular. The term has subsequently had a number of shifts in meaning. In the early 1950s and beyond, the term rhythm and blues was frequently applied to blues records. Read more on Last.fm.