Chord Changes

Well, I've decided that I want to spend some time working on my jazz chops and learning a bit more about improvisation in general. I've started to review some different material and am going over standard II-V-I changes and appropriate scale changes. We're keeping it simple right now, just using modes based from the major scale for the I chord of whatever key you're in. I think you can apply the same mentality to the pentatonic major scale (more later on that). For example, my understanding is that the II chord is always a minor 7th chord, the V is always a dominant 7th and the I is always a major 7th. The Dm7 chord uses a D dorian scale (from the key of C) and gives us a minor 3rd interval (F) and a minor 7th interval (C). The G7 chord using a G mixolyidan scale (from the key of C) and gives us a major 3rd interval (B) and a minor 7th interval (F). And finally, the Cmaj7 chord using a C ionian scale (a.k.a. major scale, from the key of C) and gives us a major 3rd interval (E) and a major 7th interval (B).
I think the thing to remember about chord changes is not so much what key the song is written in, but what are the chord changes. Where are you coming from and changing to. I'm sure there's more to it than that and I will be learning that bit later. But for now, my V7 chord will be using mixolydian, etc... It should be good practice.

• Minor 7th chords are II chords


• Dominant 7th chords are V chords


• Major 7th chords are I chords