Jazzing Up The 12-Bar Blues

When blues guys play the blues, they usually play the following progression:

I | IV | I | I |
IV | IV | I | I |
V | IV | I | V ||

In the key of C for example, this would give you the following chords

C | F | C | C |
F | F | C | C |
G | F | C | G |

One of the commonly used variations in the above progression is:

I | I | I | I |
IV | IV | I | I |
V | IV | I | V ||

Only 1 bar is different: the 2nd bar is either a I or a IV chord.
Both options are equally common.
I personally prefer playing the IV chord in the 2nd bar, because it breaks things up a bit and adds more color.

If you always wondered how to jazz up that good old blues progression, or how to make it more colorful, you will love what we’re getting into now.

Let’s start with 4 major blues examples.

As you will see, the most used technique to jazz up the blues is adding secondary dominants and interjecting II-V’s.
This creates more forward motion (momentum) in the blues progression.

You can learn more about secondary dominants here: Secondary Dominants. You would want to read up first on what secondary dominants are so everything that we’ll cover here will make more sense.

Interjecting II V I’s and adding the V7/II
In the 4th bar, the Em going to A7 going to Dm is a II V I to the Dm chord.
This creates forward motion and direction.
The IIm chord is a substitution for the IV chord. II and IV are what you call “subdominant feel” chords. They can always substitute for one another. (I will cover this in great detail in next week’s blog)
I | I | I | I |
IV | IV | I ii | iii V7/ii |
ii | V | I V/ii | ii V ||
In the key of C these are the chords:
C7 | C7 | C7 | C7 |
F7 | F7 | C7 Dm7 | Em7 A7 |
Dm7 | G7 | C7 A7 | Dm7 G7 |
Interjecting II V I’s and adding the V7/IV and V7/II
I | IV | I | V7/IV |
IV | IV | I ii | iii V7/ii |
ii | V | I V/ii | ii V ||
In the key of C these are the chords:
C7 | F7 | C | C7 |
F7 | F7 | C7 Dm7 | Em7 A7 |
Dm7 | G7 | C7 A7 | Dm7 G7 |
Interjecting II V I’s and adding the V7/III and V7/II
In the 4th bar, we’re setting up a II V I to the F chord in the 5th bar.
ii/IV means, the 2nd chord to the IV chord. The IV chord in this key, the key of C, is F. The II chord for F is Gm
The reasoning behind this is that, when we are setting up a II V I progression, we are in this case, treating what is chord number IV in the key of C, as chord number I in the II V I we are setting up to lead to that IV chord.
I | IV | I | ii/IV V7/IV |
IV | IV | I ii | iii V7/ii |
ii | V | I V/ii | ii V ||
In the key of C these are the chords:
C7 | F7 | C | Gm7 C7 |
F7 | F7 | C7 Dm7 | Em7 A7 |
Dm7 | G7 | C7 A7 | Dm7 G7 |
Adding Dim7 chords
I | IV | I | ii/IV V7/IV |
IV | #ivdim | I ii | iii V7/ii |
ii | V | I V/ii | ii V ||
In the key of C these are the chords:
C7 | F7 | C | Gm7 C7 |
F7 | F#dim7 | C7/G Dm7 | Em7 A7 |
Dm7 | G7 | C7 A7 | Dm7 G7 |
There are 2 ways you can analyze the F#dim7 here.
1. As a passing chord from F to C/G. In that case, you would need to play a C chord with the 5th in the bass so you get the bass motion F F# G
2. As a substitution for the F7 chord. Dominant chords can always be substituted with a dim7 chord up a half step from the dominant chord’s root. F#dim7 = F7b9. If you’re not sure what that means, this is explained here: The 3 Uses of the Diminished 7th Chord
Interjecting II V I’s and adding the V7/III and V7/II
I | IV | I | ii/IV V7/IV |
IV | #ivdim | I ii | iii V7/ii |
ii | V | iii V/ii | ii V ||
In the key of C these are the chords:
C7 | F7 | C | Gm7 C7 |
F7 | F#dim7 | C7 Dm7 | Em7 A7 |
Dm7 | G7 | Em A7 | Dm7 G7 |
In this example: we’re substituting the tonic I chord with the IIIm chord.
The IIIm chord is a substitution for the I chord. I and III are what you call “tonic feel” chords. They can always substitute for one another. (I will cover this in great detail in next week’s blog)
In addition: the IIIm chord (Em) is the II chord going to the V chord (A7) resolving to its I chord Dm. So be replacing the C7 chord with an Em chord, we’re setting up another II V I into the Dm chord.

Minor blues

All the above were major blues examples.
Let’s have a look at minor blues.

The Minor Blues Progression.
In minor blues, I, IV, and V are minor chords.
i | i | i | i |
iv | iv | i | i |
v | iv | i | v |
The lower case Roman numbers, always represent minor chords.
There are different ways of writing this: i or Im or I- all mean a I minor chord.
In the key of C minor, for example, this would give you the following chords.
Cm7 | Cm7 | Cm7 | Cm7 |
Fm7 | Fm7 | Cm7 | Cm7 |
Gm7 | Fm7 | Cm7 | Gm7 |
Interjecting II V I’s and adding secondary dominants:
i | ii V | i | ii/iv V/iv |
iv | iv | i | i |
iii V7/II | ii V | i | ii V ||
In the key of C these are the chords:
Cm7 | Dm7 G7 | Cm7 | Gm7 C7 |
Fm7 | Fm7 | Cm7 | Cm7 |
Em7 A7 | Dm7 G7 | Cm7 | Dm7 G7 |
More II V I’s and secondary dominants:
i | ii V | i | ii/iv V/iv |
iv | ii V | i | i V7/iii |
iii V7/II | ii V | i | ii V ||
In the key of C these are the chords:
Cm7 | Dm7 G7 | Cm7 | Gm7 C7 |
Fm7 | Dm7 G7 | Cm7 | Cm7 B7 |
Em7 A7 | Dm7 G7 | Cm7 | Dm7 G7 |

Hit me up anytime at vreny@zotzinmusic.com if you would like me to send you fun backing tracks to solo over with these arpeggios.
You’re on your way to becoming a great guitar player.
Have fun! 🙂

Conclusion

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