--- title: "12-Bar Blues Chord Progression in C, F and B♭ · Piakno" description: "The 12-bar blues is a chord form twelve measures long, built from three dominant sevenths: I7, IV7 and V7. In C they are C7, F7 and G7, played in a set order that then repeats." url: "https://piakno.com/theory/twelve-bar-blues" lang: "en" alternates: en: "https://piakno.com/theory/twelve-bar-blues.md" zh-Hans: "https://piakno.com/zh-Hans/theory/twelve-bar-blues.md" zh-Hant: "https://piakno.com/zh-Hant/theory/twelve-bar-blues.md" ja: "https://piakno.com/ja/theory/twelve-bar-blues.md" ko: "https://piakno.com/ko/theory/twelve-bar-blues.md" es: "https://piakno.com/es/theory/twelve-bar-blues.md" de: "https://piakno.com/de/theory/twelve-bar-blues.md" pt-BR: "https://piakno.com/pt-BR/theory/twelve-bar-blues.md" --- # The 12-bar blues > The 12-bar blues is a chord form twelve measures long, built from three dominant sevenths: I7, IV7 and V7. In C they are C7, F7 and G7, played in a set order that then repeats. Also called twelve-bar blues or blues progression ## What are the chords of a 12-bar blues? Three chords, one to a measure, in a set order that then repeats; a few measures vary from version to version (below). They sit on the first, fourth and fifth degrees of the key, and all three are dominant sevenths: in C, that is C7, F7 and G7. In a major key only the V chord is a dominant seventh. The blues gives the other two the same flat seventh, and that is a large part of its sound. *The three chords of the blues in C: C7, F7 and G7, each a dominant seventh.* | Line | 1st measure | 2nd measure | 3rd measure | 4th measure | | --- | --- | --- | --- | --- | | Line 1 (measures 1–4) | C7 | F7 | C7 | C7 | | Line 2 (measures 5–8) | F7 | F7 | C7 | C7 | | Line 3 (measures 9–12) | G7 | F7 | C7 | G7 | > The second measure is where versions differ. Many blues stay on C7 for all of the first four measures; the practice tool plays the common “quick change,” F7 in measure 2 and back to C7. The last measure varies too, as the next section explains. ## What is the turnaround? The last measures steer the form back to the top. Ending measure 12 on G7 puts the dominant right before the repeat, so the next chorus lands on C7 with a small resolution. That is the turnaround. Ending on C7 instead is how a blues closes, or simply settles. The practice tool offers both, each with the quick-change F7 in measure 2, and they differ only in measure 12. Jazz players often fill measures 11 and 12 with a longer turnaround, I–VI7–ii7–V7: in C, C7, A7, Dm7 and G7, two chords to a measure. The VI7 is the dominant of the ii that follows it. ## What are the chords in other keys? The roles stay the same and only the letters move. The improvisation practice starts in F, B♭ and C. | Key | I7 | IV7 | V7 | | --- | --- | --- | --- | | F major | F7 | B♭7 | C7 | | B♭ major | B♭7 | E♭7 | F7 | | C major | C7 | F7 | G7 | ## What is the jazz blues? The jazz blues keeps the form and its dominant sevenths and adds ii–V moves. Measure 4 holds two chords, Gm7 and C7: a ii–V that leads to the F7 of measure 5 (Gm7 is the ii of F). Measures 9 and 10 are Dm7 and G7, a ii–V that leads back to the C7 of measure 11 (the ii–V–I entry has the pair). Measure 12 also holds two chords, C7 and G7, so the form turns around into the next chorus. The improvisation practice plays this form at level 7. | Line | 1st measure | 2nd measure | 3rd measure | 4th measure | | --- | --- | --- | --- | --- | | Line 1 (measures 1–4) | C7 | F7 | C7 | Gm7 C7 | | Line 2 (measures 5–8) | F7 | F7 | C7 | C7 | | Line 3 (measures 9–12) | Dm7 | G7 | C7 | C7 G7 | > Players vary it further. Measure 8 can lead into the Dm7 of measure 9 with a dominant of its own: A7 (the dominant of ii) or its tritone substitute, E♭7. The G7 of measure 10 can likewise become D♭7. The chord symbol harmony practice asks for these variants at level 8. ## What are approach notes? An approach note is an outside note a half step above or below a chord tone, played just before it so that it leans into it. Over the C7 of measure 1, B is a half step under C and is not in C7, which has B♭. Play B and then C, and the B sounds like a step toward C, not a wrong note. The improvisation practice counts an outside note as resolved when the next note comes no more than two beats later, a half or whole step away, and is a chord tone, so an approach that reaches its chord tone soon enough counts and one that wanders does not. ## What is the minor blues? The minor blues has the same twelve measures, with minor seventh chords on I and IV where the major blues has dominant sevenths: in C minor, Cm7 and Fm7. Only the V stays a dominant seventh, G7, because its B natural is the leading tone that pulls back to the tonic. Measure 9 is usually A♭7, a dominant seventh on the minor key’s sixth degree, which falls a half step onto the G7 of measure 10. Measure 12 ends on G7 again as the turnaround. | Line | 1st measure | 2nd measure | 3rd measure | 4th measure | | --- | --- | --- | --- | --- | | Line 1 (measures 1–4) | Cm7 | Fm7 | Cm7 | Cm7 | | Line 2 (measures 5–8) | Fm7 | Fm7 | Cm7 | Cm7 | | Line 3 (measures 9–12) | A♭7 | G7 | Cm7 | G7 | > A common variation puts a minor ii–V in measures 9 and 10: Dm7♭5 and then G7 in place of A♭7 and G7. The chord symbol harmony practice asks for both at level 8. ## What does swing mean in a blues? Swing is a way of playing eighth notes, not a different note value. They are written evenly, but the first of each pair is held longer and the second is delayed, roughly like the first and third notes of a triplet. A blues is usually played this way, and the feel gives the same chords their relaxed, rolling motion. ## Common questions ### Why are all the chords sevenths in the blues? The flat seventh is the blues sound. With it in the I and IV chords as well as the V, all three are dominant sevenths, so the harmony keeps leaning forward and no chord sounds like a full stop. ### What is the quick change? It is a visit to the IV chord in the second measure of the form, F7 in C, before returning to C7. It breaks up the first four measures, which would otherwise sit on one chord. ### What notes can you play over a 12-bar blues? A good start is the minor pentatonic scale or the blues scale on the key’s tonic, which is C in C; the pentatonic entry explains why those notes fit over all three chords, so you do not have to change scales when the chord changes. ## You can practice this in: - [Improvise over a band · Level 1](https://piakno.com/improvise?level=1) ## Related entries - [Pentatonic and blues scales](https://piakno.com/theory/pentatonic-and-blues-scales) - [The dominant seventh chord](https://piakno.com/theory/dominant-seventh) - [Chord symbols](https://piakno.com/theory/chord-symbols) - [The ii–V–I progression](https://piakno.com/theory/ii-v-i) - [Seventh chords](https://piakno.com/theory/seventh-chords) - [Theory reference](https://piakno.com/theory)