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

or

Am | Am | Am | Am

Dm | Dm | Am | Am

Em | Dm | Am | Em

Another option to play over these changes is riffs (repeating musical ideas). If you were to play a pentatonic riff like the blues walk, it can just be moved to start on each chord root as it is played, and is a great basis to start improvising over your blues songs.

A Deeper Look at Rhythm

The ultimate goal for working on your rhythm is to comfortably play in the pocket. The pocket is more of a feeling when you play than something that can be notated, but we can work through exercises to help build your sense for it.

The general levels that I break down my rhythm work to are thus:

1) Locking with the beat

2) Accenting individual beats

3) Adding Subdivisions

4) Playing Progressions

5) Adding phrases and licks

Locking With the Beat

This is a great exercises to use as a warm up and to put you in the mindset for playing in the pocket with any given piece. Here is a tab example for the exercise. You can use any type of beat and tempo as long as you can identify and lock-in-to the kick and snare beats.

Accenting Indevidual Beats

To take finding the beat a step further, here we add a different note to accent different beats in the bar.

Subdivisions

Each beat in a Common Time piece can be broken down into 4 beats. You may have used another way to identify them, but a common way is to use 1 e +a.

1 = The beat

+ = The mid-beat accent

e and a = The second and third subdivisions

Practice finding the beat first, and then adding or writing certain subdivision variants to your bassline to get a feel for them. This is the last step to mastering your rhythm before adding phrases and progressions.