Country music is about tradition, yet its simple form lends itself to endless variations on similar themes. Like blues -- the two genres often shared themes, melodies and songs -- country is a simple music at its core. Most of its songs are built around three chords and a plain melody, but these forms are so basic, they allow for many different styles, from the gritty sounds of honky tonk to the jazzy improvisations of Western Swing. Country music grew out of American Southern folk music, both Appalachian and blues, and old-time country was simple and folky, with just guitars and fiddles. As the genre progressed, old time music evolved into the rhythmic guitar-and-fiddle driven traditional country that became the foundation of modern country music, from honky tonk and Western Swing to the pop-oriented Countrypolitan and rock-inflected Bakersfield Sound.