The I VI II V Progression

In the major II V I page, we looked at the process of forming chords within the major scale and using them to create progressions. Diatonic chord structure means that we construct chords solely from the notes of the relative scale and non-diatonic structure uses notes outside the relative scale. In this page, are a few examples of the various ways you can alter the chord quality within the standard progression of the I VI II V. But first, recap on the chords built from the major scale below:

I VI II V Example 1

I VI II V Example 2

I VI II V Example 3

As you can see the tonality of the chords can be changed, in example 1 for instance the C major scale could be used as a means to improvise with over the entire chord progression or, the C ionian, A aeolian, D dorian and G mixolydian respectively, but in example 2, the VI chord is non diatonic so you would have to make the change applying a scale other than the C major scale or A aeolian to it. In example 3 you would have to use three scales that reside outside the C major scale.

Here’s another example :

I VI II V Example 4

At times you may encounter roman numerals that indicate the tonality of the chord eg. bIII 7 in example 4 is the 3rd chord built on the C major scale which normally would be an E min7, but in this instance a substitution has occurred. The tonality of the regular III chord has been changed from min7 to dominant 7 also the natural E that is inherent from the C major scale has been flattened by a semitone to Eb. Another way to look at this substitution is that it is a tritone substitution. Normally in the key of C the VI chord in a I VI II V would be some kind of A chord, in example 4 however, the VI chord has been substituted for a chord that exists a tritone away (3 tones) as has the V chord, Db7 being a tritone away from G7. Tritone substitution was a favourite amongst the bebop players of the 1940s and is a useful alternative in the formation of certain chords and as a device for soloing.

Let´s look at how tritone substitution works.

When soloing over a I VI II V chord progression you have multiple choices of scales to use, if we momentarily recap on example 4

I bIII 7 II 7 bII 7
C Maj 7 Eb 7 D 7 Db 7

Scale choice for the I chordC major scale

Scale choice for the bIII 7 chord assuming it has been substituted for the A7 and not the A minor would be Eb lydian dominant (see jazz melodic minor modes for ' Lydian Dominant'). If the A7 was present as the VI chord and because of its impulse towards the minor II chord you might opt for a high tension scale like the A altered scale, (see jazz melodic minor modes 'Altered Scale’) the Eb lydian dominant is related to the A altered scale and both scales are derived from the Bb jazz melodic minor scale.

Scale choice for the II7 chordD mixolydian

Scale choice for the bII7 chordDb lydian dominant

So far we have looked at the major and minor II V I and the I VI II V progressions, there are many more but, if you can, using the information provided confidently solo over these progressions you should be on your way to getting that jazz sound and that in itself should hopefully inspire you to learn some more.