12-bar blues

The 12-bar is an extremely common structure when playing blues. A 12-bar blues is performed, as the name implies, by playing twelve bars in a given arrangement that are repeated through a song. There are plenty of arrangements, based on chord progressions, to use.

A 12-bar blues is commonly written out by the chords that are used. You can also play scales over these chords.

Standard 12-bar blues

12 Bar Blues structure
The numbers are just to illustrate the order of bars. You could, for instance, play with four beats per bar like this:

(1) E7 / / / - (2) E7 / / / - (3) E7 / / / - (4) E7 / / / -
(5) A7 / / / - (6) A7 / / / - (7) E7 / / / - (8) E7 / / / -
(9) B7 / / / - (10) A7 / / / - (11) E7 / / / - (12) E7 / / /

In the key of C, the chords would instead be C7, F7 and G7. See Appendix A for standard 12-bar blues in all keys.

12 Bar Blues in E sound example. The 12 bar section are played two times with turnarounds in the last measure the first time.

As an suggestion, use the E Pentatonic Minor Blues and/or the E Pentatonic Major Blues scales to improvise over the 12-bar blues track.

E Major Pentatonic Blues scale diagram E Pentatonic Blues scale diagram

Playing scales over the 12-bar blues

You can either play one scale over all bars or change scale as the chord change. In addition, it is a common method to put extra empathize on tones included in the actual chord that is being played. You need to develop your ear for this. Try to play the chords with your left hand and notes from the scale with your right.

12-bar blues in minor

12 Bar Blues structure
You could, for instance, play with four beats per bar like this:

(1) Em / / / - (2) Em / / / - (3) Em / / / - (4) Em / / / -
(5) Am / / / - (6) Am / / / - (7) Em / / / - (8) Em / / / -
(9) B7 / / / - (10) Am / / / - (11) Em / / / - (12) Em / / /

12 Bar Blues in Em sound example. The 12 bar section are played two times with turnarounds in the last measure the first time.

For improvising over this 12-bar blues, you can use the Em Pentatonic Blues Scale.

E Pentatonic Blues scale diagram

As already said, there are endless ways to vary the twelve bars (it must not necessarily be 12 bars, the 16-bar blues structure is also popular). Also to be familiar with, when learning the 12-bar structure, is the turnaround as in the next example. See Appendix B for standard 12-bar minor blues in all keys.

12-bar blues with turnaround

12 Bar Blues structure
The novelties are only at the end: in the last two bars you should play five measures of the E7 chord and then change to B7 for the last three.

(1) E7 / / / - (2) E7 / / / - (3) E7 / / / - (4) E7 / / / -
(5) A7 / / / - (6) A7 / / / - (7) E7 / / / - (8) E7 / / / -
(9) B7 / / / - (10) A7 / / / - (11) E7 / / / - (12) / B7 / /

The last time the structure is played in the song, it should end on an E chord.

12-bar jazz-blues

12 Bar Blues structure
A more detailed presentation, including measures in the bars:

(1) C7 / / / - (2) F7 / / / - (3) C7 / / / - (4) C7 / / / -
(5) F7 / / / - (6) F7 / / / - (7) C7 / / / - (8) A7 / / / -
(9) Dm7 / / / - (10) G7 / / / - (11) Em7 / / / - (12) Dm7 / G7 /

In this example, some extra chords were added to the 12-bar structure and as a result we got a mix of blues and jazz.

8-bar ragtime

The 8-bar progression is an alternative to the 12-bar version. The 8-bar is often used in ragtime, which you can see an example of below:

(1) C / / / - (2) E7 / / / - (3) A7 / / / - (4) / / / / -
(5) D7 / / / - (6) G7 / / / - (7) C / / / - (8) G7 / / / -

Notice how this progression is based on the descending fifth intervals.

Appendix A

The standard 12-bar blues with three chords in all keys.

I IV V
A7 D7 E7
A#7 / Bb7 D#7 / Eb7 F7
B7 E7 F#7
C7 F7 G7
C#7 / Db7 F#7 / Gb7 G#7 / Ab7
D7 G7 A7
D#7 / Eb7 G#7 / Ab7 A#7 / Bb7
E7 A7 B7
F7 Bb7 C7
F#7 / Gb7 B7 C#7 / Db7
G7 C7 D7
G#7 / Ab7 C#7 / Db7 D#7 / Eb7

It is common to play seventh chords in blues, but it is possible to substitute seventh with, for example, ninth.

Appendix B

The standard 12-bar blues with three chords in all minor keys.

I IV V
Am Dm E7
A#m / Bbm D#m / Ebm F7
Bm Em F#7
Cm Fm G7
C#m / Dbm F#m / Gbm G#7 / Ab7
Dm Gm A7
D#m / Ebm G#m / Abm A#7 / Bb7
Em Am B7
Fm Bbm C7
F#m / Gbm Bm C#7 / Db7
Gm Cm D7
G#m / Abm C#m / Dbm D#7 / Eb7

The minor chords can be substituted with, for example, minor seventh chords.

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