Country music, also known as country and western (or simply country), and hillbilly music, is a genre of popular music that originated in the Southern United States in the early 1920s. It takes its roots from genres such as American folk music (especially Appalachian folk and Western music) and blues. Country music often consists of ballads and dance tunes with generally simple forms, folk lyrics, and harmonies mostly accompanied by string instruments such as banjos, electric and acoustic guitars, steel guitars (such as pedal steels and dobros), and fiddles as well as harmonicas. Blues modes have been used extensively throughout its recorded history. According to Lindsey Starnes, 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. In 2009 in the United States, country music was the most listened to rush hour radio genre during the evening commute, and second most popular in the morning commute. The term country music is used today to describe many styles and subgenres. The origins of country music are found in the folk music of working class Americans and/or blue-collar American life, who blended popular songs, Irish and Celtic fiddle tunes, traditional English ballads, cowboy songs, and the musical traditions of various groups of European immigrants.