JA-027 • II-V-I Chord Sequences

[kaoD]

To everyone asking about the A7 instead of Amin7:

I'm not sure if what I'm going to say is true, but it's probably. Notice A is actually the V in the key of D which is the next chord in the sequence. You can alter the A7 chord too, since it's functioning! And, if I'm not mistaken, you can use D7 instead of Dmin7 too, because D is the V in the key of G, and probably altering it would work too (as would altering the G7 which is the V of C)

You can go all crazy around these sequences!

Please, bear in mind that whatever I say (or whatever real theory says) might be wrong. Let your ears be your judges!

[TB-AV]

Hey Justin,

This jazz series is really helping me understand so much of the theory behind chords, just a quick question though; in the sequence where you talk about 'comping' the IIm V7 Imaj sequence is followed by a A7 (which would be a VI7), sounds great but why does this work? surely the VI chord should be a m7 chord e.g. Am7 and not a dominant.

He is playing ii V7 I then in that example he follows it with a VI7

vi ii V I is very popular progression so basically he is playing a vi ii V I on the second go round. However to make the vi to ii more powerful. In other words to make that vi pull really hard to resolve to that ii he makes it a Dominant chord. All dominant chords are Major. The 3rd degree is the leading tone to the chord to which it will resolve. Am7 has a 3rd that is C. A7 has a 3rd that is C#. The chord resolves to a D chord next.   C# to D  A7 Dm7 G7 Cmaj7. It gives the whole thing a feel of resolve resolve resolve resolve in chord pairs so to speak.

[justinguitar]

It's called a secondary Dominant - I just added that to my jazz to do list!