Blues is a music genre originated by African Americans in the Deep South of the United States around the end of the 19th century. The genre was developed from roots in West African musical traditions, African-American work songs, chants, spirituals, and folk music of white Americans of European heritage. The blues is characterized by a call-and-response pattern, the blues scale, and a specific chord progression, of which the twelve-bar blues is the most common. Blues has been a major influence on later American and Western popular music, finding expression in ragtime, jazz, big bands, rhythm & blues, rock & roll, country music, and conventional pop songs.