Twelve-bar blues
The twelve-bar blues (or blues changes) is one of the most prominent chord progressions in popular music. The blues progression has a distinctive form in lyrics, phrase, chord structure, and duration. In its basic form, it is predominantly based on the I, IV, and V chords of a key. Mastery of the blues and rhythm changes are "critical elements for building a jazz repertoire".[1]
For the Scott Weiland album, see 12 Bar Blues (album). For the Patrick Neate novel, see Twelve Bar Blues (novel).Background[edit]
The blues originated from a combination of work songs, spirituals, and early southern country music.[2] The music was passed down through oral tradition. It was first written down by W. C. Handy, an African American composer and band leader. Its popularity led to the creation of "race records" and the popularity of blues singers like Bessie Smith and Ma Rainey.[3] The style of music heard on race records was later called "rhythm and blues" (R & B). As the music became more popular, more people wanted to perform it. General patterns that existed in the blues were formalized, one of these being the 12-bar blues.[2]
The basic progression for a 12-bar blues may be represented in several ways. It is shown in its simplest form, without the common "quick change", turnarounds, or seventh chords. For variations, see the following section.
Melodic line[edit]
As the chords of a 12-bar blues follow a form, so does the melodic line. The melodic line might just be the melody of the piece or it might also include lyrics. The melody and lyrics frequently follow an AA'B form, meaning one phrase is played then repeated (perhaps with a slight alteration), then something new is played.[14] This pattern is frequently used in the blues and in musical genres that have their roots in the blues.[15]