Blues music originated in the Deep South in the late 19th century. Developed by African Americans, the blues incorporated spirituals, work songs, field hollers, shouts, chants, and rhymed simple narrative balladsm while expressing the melancholy and the yearnings of the African-Americans that suffered slavery and segregation for more than 200 years.
One aspect of blues is the 12 bar chord progression. The blues progression has a distinctive form in chord structure, duration, phrase, and lyrics. It is one of the most prominant chord progressions in popular music. It consists of 3 main chords of any key; I, IV, and V and it is typically in a 4/4 time signature.