HOW TO SOLO ON A JAZZ BLUES – PART 4

Chord extensions & substitutions

By Travis Jenkins, JMI lecturer

(Guitar, Jazz Materials, Ensemble, Jazz Composition)

Part 1 of How to Solo on a Jazz Blues focused on using the melody and different formations of the major and minor blues scale to improvise over the basic blues chord progression. In Part 2 of How to Solo on a Jazz Blues, we looked at how we can use our understanding of chord tones to create weaving arpeggios. We followed up in Part 3 of How to Solo on a Jazz Blues with using Guide Tones, Approach Tones and Enclosures.

For this final part of the How to Solo on a Jazz Blues series, let’s look at using Chord extensions and substitutions…

We’ve looked at some of the fundamental principals behind outlining chord changes, so now let’s change the chords!

By changing either the chord-scale relationship of a chord, or by substituting or superimposing different chord changes over the existing chords, we can get a whole range of exotic sounds to create varying degrees of tension and release.

Melodic Minor Modes

Melodic Minor modes can be applied in certain ways to change the extensions (9, 11, 13) and chord-scale relationships of some of our diatonic modes.

For example, the 4th mode of Melodic Minor, Lydian Dominant can be applied over (as the name suggests) a Dominant 7th chord.  It has the same interval structure as the Mixolydian mode except that it has a #4 (#11).

C Lydian Dominant

Similarly, the 7th mode of Melodic Minor, Altered Dominant can also be applied over a Dominant 7th chord, but typically one which resolves to its respective tonic chord.  The Altered Dominant scale has both a flat and sharp 9th, and both a flat and sharp 5th.

A Altered Dominant

To bring out some of these sounds we can start to think about targeting the extensions of our chords in addition to our targeting of the chord tones.   The same logic applies here except we are now landing on the extensions on downbeats, as well as the chord tones.

Here we have taken the previous example solo but altered it slightly to include the use of extensions and scale alterations:

In addition to this, we can completely substitute entirely new chord changes over the preexisting ones.  There are varying degrees of theory involved in how different chord substitutions work but a very commonly used one is the Tritone Sub.  Each dominant chord shares the same guide tones as another whose root notes are exactly one tritone apart.  For example, G7 and Db7 both share the same guide tones B and F and are interchangeable.  To take this one step further, we can precede each of these substituted chords with their respective ii-7 chords.

Can you work out some of the substitutions being used on this Wes Montgomery tune “Missile Blues”? https://www.youtube.com/watch?v=92U3gMK4IgU

Here’s an example of a heavily reharmonised C blues using different applications of tritone substitutions and other substitutions.

I hope you’ve enjoyed the How to Solo on a Jazz Blues blog series! Try writing a solo over these changes using the other techniques from this series to see what you can come up with!

Feel free to reach out to us with any questions you have about the concepts discussed in this series. If you’d like to learn some more, consider one of JMI’s course options available!