Country music developed in the early 20th century from genres including blues, western, and Appalachian folk music. Country and western genres initially emerged separately in the southeastern and southwestern US, respectively, before combining. Early country recordings from the 1920s were sometimes called hillbilly music. Major early artists included the Carter Family and Jimmie Rodgers. The genre continued developing through the 1930s-1960s with the popularization of the Grand Ole Opry and the emergence of subgenres like rockabilly, the Nashville sound, and country rock. Contemporary country incorporates pop and rock influences and remains a commercially successful genre. Bluegrass also evolved in the 1930s and maintains traditional instrumentation while some artists incorporate new