The following is a classic GP lesson from jazz guitar master Jake Hertzog's column, Hey Jazz Guy.
Hey Jazz Guy,
How can I turn my cool rock chords into some sweet jazz changes? – Rockstar in Reno
Dear Rockstar,
Reharmonization is one of the hippest ways to alter a chord progression. Let’s take some chords and follow their transition from pop rock to über-jazz.
We will start with a progression using basic guitar voicings [Ex. 1]. The next thing to do is add 7ths to each chord [Ex. 2]. Then, substitute chords based on the cycle of 4ths [Ex. 3].
We’re in 5/4 now to make room for the changes. In this case we will sub Dm7 for F and slip in an Em7 before Am7. This creates a cycle of 4ths progression in the bass (E, A, D, G). At this point we want to break the tonality of C major, [Ex. 4] by turning some of the minor chords into dominants (E7, D7).
Now for the really fun part, adding the tensions. If we just take a sample off the spice rack [Ex. 5] (season to taste), we get some cool altered tensions (#9, b13) on the dominants, and lovely 9ths and 6ths on the major and minors.
Now we have a jazzy sounding chord sequence, but we can go further by substituting the tri-tone subs [Ex. 6] for E7 and D7 using Bb13 and Ab7(#11) instead.
II-V progressions can resolve down a half-step, in the same way dominants can, so next we can treat the IIm-V as if it were one dominant chord using Ebm7 and Ab7 to lead to Dm9 [Ex 7].
To go off the deep end, we also have some Coltrane triads over a pedal tone [Ex. 8].
There are infinite ways to reharmonize, but these ideas should give you a rocking place to start.
Jazz hard!
