Country music is a genre of American popular music that began in the rural regions of the Southern United States in the 1920s. It takes its roots from southeastern American folk music and Western music. Blues modes have been used extensively throughout its recorded history. Country music often consists of ballads and dance tunes with generally simple forms and harmonies accompanied by mostly string instruments such as banjos, electric and acoustic guitars, fiddles, and harmonicas.
The term country music gained popularity in the 1940s in preference to the earlier term hillbilly music; it came to encompass Western music, which evolved parallel to hillbilly music from similar roots, in the mid-20th century. The term country music is used today to describe many styles and subgenres. In 2009 country music was the most listened to rush hour radio genre during the evening commute, and second most popular in the morning commute in the United States.