The 12-bar blues is one of the most popular chord progressions in popular music.

It has a distinctive form in both lyrics and chord structure which has been used in songs in many forms of popular music. Most commonly, lyrics are in three lines, with the first two lines almost the same with slight differences in phrasing and interjections: :Yes, I hate to see that evening sun go down ::W.C. Handy's "St. Louis Blues"

The chord progression is simple to identify after some study and attention as it rises and falls in a regular and very familiar pattern. The blues can be played in any key, but guitar and bass players prefer open chords, that is, chords with several open strings: E-A-B7 or A-D-E7. Keyboardists may prefer C-F-G7 or G-C-D7. (These are termed, respectively, the tonic, subdominant, and dominant in the discussion below.)

The 12-bar blues chord progression is the basis of thousands of songs, not only formally identified blues songs such as "St. Louis Blues", "Shake, Rattle and Roll" and "Hound Dog", but also gospel songs, such as "I'm So Glad (Jesus Lifted Me)", jazz classics like "Flying Home" and "Night Train", pop and rock songs, including Glenn Miller's "In the Mood", The Beatles' "Why Don't We Do It In The Road?", and The Clash's "Should I Stay or Should I Go", Top 40 hits like Fabian's "Turn Me Loose", "At the Hop" by Danny and the Juniors, and the "Theme from Batman". The vast majority of boogie woogie compositions are 12-bar blues, as are many instrumentals, such as "Rumble" and "Honky Tonk".

Many songs written in the blues chord progression do not use the three-line form of lyrics. For instance, "I'm Movin' On" has a verse in the first four bars and a chorus in the final eight bars: :Means your true lovin' daddy ain't comin' back. :You were flyin' too high for my little old sky "At the Hop" has a twelve-bar verse followed by a twelve-bar chorus.