The blues as a form
The blues is a genre, a melodic language (blue notes, bending) and a form: the most common is the 12-bar blues, but 8-, 16- and 24-bar forms also exist. This entry looks at form and arrangement; for detailed harmony and jazz substitutions see "The blues: 12-bar form and harmony," "The jazz blues," "The minor blues" and "Bird blues."
The 12-bar blues and AAB lyrics
The basic harmonic scheme, in A (A7 = I7, D7 = IV7, E7 = V7):
| Bars | 1–4 | 5–8 | 9–12 |
|---|---|---|---|
| Chords | I7 I7 I7 I7 | IV7 IV7 I7 I7 | V7 IV7 I7 V7 (turnaround) |
| Lyrics | A: line | A: the same line repeated (sometimes varied) | B: answering line, which closes with a rhyme |
Each 4-bar line has a question–answer structure: the singer sings for about 2 bars, then the instrument answers (fill) in the other 2. This is the call and response that comes from work songs and African American music.
Variants of the 12-bar form:
- Quick change (quick four): IV7 in bar 2 (I7 – IV7 – I7 – I7…).
- Turnaround in bars 11–12: I7 – V7, or I7 – VI7 – ii7 – V7, or the chromatic descent typical of Chicago blues (A7 – A7/G – D/F♯ – Dm/F – A/E – E7).
- The minor blues (Im7, IVm7, ♭VI7–V7).
The 8-bar blues
- Common scheme: I – V – IV – IV | I – V – I – V, or I – I7 – IV – IVm | I – V7 – I – V7.
- Examples: "Key to the Highway" (recorded by Jazz Gillum and by Big Bill Broonzy in 1940–41; later Eric Clapton), "Trouble in Mind," "Heartbreak Hotel" (Elvis Presley, 1956).
- Lyrics are generally AB (two lines).
The 16-bar blues
- It is often obtained by lengthening the first part (8 bars of I7 instead of 4) or by repeating bars 9–10.
- Example: Herbie Hancock, "Watermelon Man" (1962), a 16-bar blues with a final section that repeats the cadence.
Intros, stop-time and endings
- Intro "from the V": you start from the last 4 bars of the form (V7 – IV7 – I7 – V7), so the first chorus begins on the tonic.
- Riff intro: 2 or 4 bars of the main riff on I7.
- Stop-time: in the first 4 bars of the chorus the band plays only the first beat of each bar (or 2 beats), leaving the vocal or soloist exposed: a classic for middle choruses.
- Endings: chromatic descent on the V (E7 – F7 – E7 or ♭II7–I7: B♭7 – A7), guitarist's trill, a held I9 or I7♯9 chord; in rock 'n' roll, the "repeat" ending on the last two bars.
The form of a blues song (arrangement)
- Intro (4 bars: V–IV–I–V or riff).
- Sung chorus 1 (12).
- Sung chorus 2 (12).
- Guitar or harmonica solo (1–3 choruses).
- Sung chorus with stop-time or low dynamics.
- Final chorus (often a full-volume "shout").
- Ending with turnaround and a closing chord.
In jazz the blues follows the head–solos–head logic (see the dedicated entry) with 12-bar themes played twice.
Typical grooves
- Shuffle (triplets with the first and third notes, swing at around 66%): Chicago blues, Texas blues.
- Slow blues in 12/8: "Red House" by Jimi Hendrix, B. B. King.
- Straight eighths / rock: "Johnny B. Goode" (Chuck Berry, 1958), built on the 12-bar form.
- Boogie-woogie: ostinato bass in eighth notes (root, third, fifth, sixth, seventh).
Exercise for a producer
In FL Studio, create a complete blues form in A at 95 BPM with 60–66% swing: intro from the V, two choruses with a vocal or lead that leaves 2 bars of space for each line (call and response with a guitar), a solo chorus, a stop-time chorus (only beat 1 of each bar for drums and bass), a final chorus and an ending with B♭7 – A7. With the same structure, try writing an 8-bar blues-rock song.
Related entries
The blues: 12-bar form and harmony, The jazz blues, The minor blues, Bird blues, Head–solos–head in jazz, Call and response, Blues scales, Shuffle and swing: percentages and programming.