12-Bar Blues in A (A)
Classic twelve-bar blues structure with tonic, subdominant and dominant
This twelve-bar progression is an authentic blues form, not four repeating chords. Measures one through four establish tonic A7. Measure five shifts to subdominant D7 for two bars before returning to A7. The final four measures build the turnaround cadence through E7, D7, A7 and the turnaround chord E7 on measure twelve.
What the bass plays, bar by bar
The progression
- A7
I7 · Bar 1-4, 7-8, 11
- D7
IV7 · Bar 5-6, 10
- E7
V7 · Bar 9, 12
It runs in 4/4 at 116 beats per minute, so each bar lasts about 2.1 seconds and the whole round about 24.8.
Bar by bar
| Bar | Chord | Notes |
|---|---|---|
| 1 | A7 | A1C#2E2F#2 |
| 2 | A7 | A1C#2E2G2 |
| 3 | A7 | A1C#2E2F#2 |
| 4 | A7 | A1C#2D2D#2 |
| 5 | D7 | D2F#2A1B1 |
| 6 | D7 | D2C2B1G#1 |
| 7 | A7 | A1C#2E2F#2 |
| 8 | A7 | A1G1F#1F1 |
| 9 | E7 | E1G#1B1D2 |
| 10 | D7 | D2F#2A1G#1 |
| 11 | A7 | A1C#2E2A1 |
| 12 | E7 | E1G#1B1D2 |
Notes with a dotted border are not part of the chord.
Where each chord sits
- A7
Bar 1, A7.
The root A1 sits on open string 3 and the fifth E2 on string 2, fret 2.
The walking line plays A1, C#2, E2 and F#2.
F# is not a note of A7.
- A7
Bar 2, A7.
The root A1 sits on open string 3 and the fifth E2 on string 2, fret 2.
The walking line plays A1, C#2, E2 and G2.
- A7
Bar 4, A7.
The root A1 sits on open string 3 and the fifth E2 on string 2, fret 2.
The walking line plays A1, C#2, D2 and D#2.
D and D# are not notes of A7.
The last note sits a semitone from the first note of D7.
- D7
Bar 5, D7.
The root D2 sits on open string 2 and the fifth A1 on open string 3.
The walking line plays D2, F#2, A1 and B1.
B is not a note of D7.
- D7
Bar 6, D7.
The root D2 sits on open string 2 and the fifth A1 on open string 3.
The walking line plays D2, C2, B1 and G#1.
B and G# are not notes of D7.
The last note sits a semitone from the first note of A7.
- A7
Bar 8, A7.
The root A1 sits on open string 3 and the fifth E2 on string 2, fret 2.
The walking line plays A1, G1, F#1 and F1.
F# and F are not notes of A7.
The last note sits a semitone from the first note of E7.
- E7
Bar 9, E7.
The root E1 sits on open string 4 and the fifth B1 on string 3, fret 2.
The walking line plays E1, G#1, B1 and D2.
- D7
Bar 10, D7.
The root D2 sits on open string 2 and the fifth A1 on open string 3.
The walking line plays D2, F#2, A1 and G#1.
G# is not a note of D7.
The last note sits a semitone from the first note of A7.
- A7
Bar 11, A7.
The root A1 sits on open string 3 and the fifth E2 on string 2, fret 2.
The walking line plays A1, C#2, E2 and A1.
How the root moves
A1 → D2 → A1 → E1 → D2 → A1 → E1
The roots are A1, D2, A1, E1, D2, A1 and E1. A1 to D2 goes up five semitones, D2 to A1 goes down five semitones, A1 to E1 goes down five semitones, E1 to D2 goes up ten semitones, D2 to A1 goes down five semitones and A1 to E1 goes down five semitones.
The lowest note of the circle is E1 and the highest G2. It uses strings 4, 3, 2 and 1. Strings 4, 3, 2 and 1 ring open at some point.
12-Bar Blues in A (A) line for electric bass
One bar per chord with the root and fifth line for four-string electric bass (E, A, D, G).