form of U.S. music originated by black Americans in the South. As a music form, the blues is typified by a melancholy state of mind and 8-, 12-, or 32-bar harmonic progressions that form the basis for blues improvisation. Another characteristic element is the “blue note,” a lowered third, seventh, or sometimes fifth degree of what would otherwise be a major scale. Derived from Southern work songs, the vocal style of the blues powerfully conveys both sorrow and defiance. The blues evolved into various forms, including country and urban, and had a profound impact on the development of rock and roll.