Hey Jazz Guy,
How can I turn my cool rock chords into some sweet jazz changes? –Rockstar in Reno
Reharmonization is one of the hippest ways to alter a chord progression. Let’s take some basic chords and follow their transition from pop-rock to uber-jazz. We will start with a progression [Ex 1], using basic guitar voicings. The next thing to do is add 7ths to each chord [Ex 2]. Then, substitute chords based on the cycle of 4ths [Ex 3], in this case we will sub Dmin7 for F and slip in an Emin7 before Amin7. 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 of 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. Two-Five progressions can resolve down a half-step, in the same way dominants can, so next we can treat the ii-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 have some Coltrane triads over a pedal [Ex 8]. There are infinite ways to reharmonize, but these ideas should give you a rocking place to start. Jazz Hard!
Link to PDF Example: HJG Pop Reharm