Blues is a vocal and instrumental form of music based on the use of the blue notes and a repetitive pattern that most often follows a twelve-bar structure. It emerged in African-American communities of the United States from spirituals, work songs, field hollers, shouts and chants, and rhymed English and Scots-Irish narrative ballads. The use of blue notes and the prominence of call-and-response patterns in the music and lyrics are indicative of African influence. The blues influenced later American and Western popular music, as it became part of the genres of jazz, bluegrass, rhythm and blues, rock and roll, hip-hop, and pop songs.
