The Blues

The 12 Bar Blues

The 12 Bar Blues is a classic progression in blues music. In the simplest sense, it is a 3 chord progression that lasts 12 bars, or 12 counts of 4 beats. The primary things to know when playing a 12 Bar Blues is the key you're in (determining your chords) and the structure of the chord changes (which will stay the same here). The 12 bars are broken up like this:

I (1st chord) - 4 bars

IV (4th chord) - 2 bars

I - 2 bars

V (5th chord) - 1 bar

IV - 1 bar

I - 1 bar

V - 1 bar (The Turnaround)

The bar count can also be taken as a ratio (i.e if you only play the first chord for 2 bars, all the other bar counts would also half). When you hear a shuffle/swing/blues rhythm, these beats are often counted on the kick and snare drum.

To determine now what chords we are playing, we need to look at the major scale. Here is a simple diagram showing the major scale.

The 'R' stands for Root, or starting note. This note determines what key we are in. The root here is the 3rd fret of the low E string, which is a G, making this a G major scale. The numbers on the rest of the notes show how far away they are from the root. We are only concerned with the root, p4 (fourth) and p5 (fifth).

Take a look back at the chords in the 12 bar blues: I, IV and V (1, 4 and 5). If for example then, I wanted to play a 12 bar blues in A, I would start my major scale on an A note, and use the shape the find out what note the 4th and 5th are (in this case they're D and E). This gives me all the chords I need.

I = A

IV = D

V = E

So my 12 Bar Blues in A is:

A | A | A | A

D | D | A | A

E | D | A | E

More Options For Your I, IV, V

Now that you know how to play a 12 bar blues, we want to have a look at the different styles you can play it in. 

The first, and simplest harmonically is to just play all the chords as major or minor chords depending on the emotion you want. A major blues progression will sound happier than a minor blues progression. Think Johnny B. Goode (Chuck Berry) and Thrill is Gone (BB King). In A, that would either be:

A | A | A | A

D | D | A | A

E | D | A | E


Am | Am | Am | Am

Dm | Dm | Am | Am

Em | Dm | Am | Em

Another option for your chords is the play 7th chords (blues chords). A Seventh chords is a major chord with a flattened 7th note, creating that bluesy/jazzy dissonance. You can either play your 12 Bar Blues with ALL seventh chords, or throw them in and mix and match to create new and interesting progressions.

Here are all your 7th Chord variants:

Finally, you can also apply riffs (repeated musical parts) to each chord position. This is the basic blues shuffle riff, but once you learn a few variations on this, there really is no end to how much you can do with it!

More Keys

Here's examples of I, IV and V chords in other keys. (All of the chords you need to play these are on your 7th chord chart).

A) I = A    IV = D    V = E

C) I = C    IV = F    V = G

D) I = D    IV = G   V = A

E) I = E     IV = A   V = B

G) I = G    IV = C   V = D