Blues encompasses a variety of musical styles and is an essential building block in almost all genres of American music, including jazz, country, bluegrass, rhythm and blues, and rock and roll. Blues music, or the blues, was born in the American South in the latter decades of the nineteenth century. It became popular throughout the United States in the early 1910s, eventually developing into many varieties, including country blues, boogie-woogie, urban blues, gospel blues, Memphis blues, Chicago blues, swamp blues, and more.
Musically, blues can be partially defined by the use of the five-note, pentatonic “blues scale,” prevalent in West African music, and the use of microtones between these notes. There are also some standard song forms, including 12-bar and 16-bar patterns, though many blues songs do not adhere to these. The blues evolved from earlier African American musical expressions, including work songs, field hollers, dance music, spirituals, and shouts. While commonly perceived as sorrowful, blues music includes songs for dancing, either upbeat or slow and sexy, comic songs, joyful songs, and more.