Country music originated in the southern United States and Appalachian Mountains, with roots in folk, Celtic, gospel and old-time music. It evolved rapidly in the 1920s and the term "country music" became widely used in the 1970s. Rock music developed in the 1940s-1960s from roots in rock and roll, rockabilly, rhythm and blues, country music and other influences. Jazz originated in the early 20th century from the combination of African and European music traditions in African American communities in the southern United States. Classical music broadly refers to mainstream Western liturgical and secular music from the 9th century to present, with central norms codified between 1550-1900.