Like ragtime, the blues was an important influence on the development of jazz. A highly expressive, predominantly vocal tradition, blues songs expressed the stories and emotions of African-Americans at the beginning of the 20th century. The blues were not only a type of music, but a state of mind and way of life for many African-Americans during this time.
A blues songs usually includes words which form a three-line stanze. The first line is sung twice, the third rhymes with the first two (aab form). The melody is performed over a 12-bar chord progression consisting of three chords built on the 1st, 4th, and 5th notes of the major scale. These three chords are referred to by the Roman numerals I, IV, and V. The distinct sound of the blues melody is in large part due to the use of notes outside the major scale, called "blue notes."

Usually blues vocalists accompanied themselves on the guitar or sang with instrumental accompaniment of guitar, piano, harmonica, or sometimes homemade instruments. Blues performed on the trumpet or saxophone, for example, often imitate the vocal effects of blues singers by bending pitches, rasping, and recreating the growl of the voice.
Important blues musicians of the early twentieth century include Ma Rainey, Bessie Smith, and W.C. Handy.
Did you know?
Many early blues performers toured as a part of the T.O.B.A. Circuit. The Theater Owners Booking Association was an organization that booked black performers.