What is blues

Blues is the name given to both a musical form and a music genre that originated in African-American communities of primarily the Deep South of the United States at the end of the 19th century from spirituals, work songs, field hollers, shouts and chants, and rhymed simple narrative ballads. The blues form, ubiquitous in jazz, rhythm and blues, and rock and roll, is characterized by specific chord progressions, of which the twelve-bar blues chord progression is the most common. The blue notes that, for expressive purposes are sung or played flattened or gradually bent in relation to the pitch of the major scale, are also an important part of the sound.