How to transition back and forth between relative major and minor 2-5-1?

Question

I'm experimenting with nicely transitioning between a major and minor 2-5-1, at this point I'm purely interested in harmony.

The 2 progression I'm trying to transition between (technically 1-2-5):

Cmaj7 | Cmaj7 | Dm7 | G7   ->   Am7 | Am7 | Bmin7b5| E7  ->  Cmaj7 ...
                      ^^                             ^^

And I'm curious what are my options in the highlighted positions to transition nicely to the next.

Going from major to minor using the 5 of the following minor chord sounds very solid:

Major to minor:

Cmaj7 | Cmaj7 | Dm7 | E7
                      ^^

But going back from minor to major I can't really find a chord there that works well.

I tried the same strategy as before (using the 5 of the next chord):

Minor to major v1:

Am7 | Am7 | Bmin7b5| G7
                     ^^

And tritone substitution

Minor to major v2:

Am7 | Am7 | Bmin7b5| Db7
                     ^^^

What are the "theoretically correct" options here?

Answer 1

A couple that spring to mind: V7+ > I, and Io > I.

The first still uses a kind of V>I, but with a little more conviction.

The second, though non-diatonic, sounds quite convincing. Can't see any other 'theoretically correct' options - that sound convincing, anyway.

Answer 2

The problem here is that the way you have the progression the 2-5’s want to go back to the original 1, not 1 of the relative. The reason the G7 works well is because it is both a bVII of Am and it is also a deceptive cadence. The E7 to C is not convincing because the leading tone resolves to the ^6 of C, which is not part of a Cmaj7. Even if you resolve to a C6 it still isn’t very satisfying because the ^6 is more of a color note in a C major chord. The E-C root motion also leaves something to be desired.

The most obvious and smooth solution is to precede each chord with its native 2-5.

Cmaj7 |Cmaj7 |Bm7b5 |E7 |Am7 |Am7 |Dm7 |G7 :||

If you want to maintain the ii chords you have then another suggestion is to play Bm7b5 for both of the last 2 bars or replace the E7 in your final bar with a Bo7 for a little voice leading. Both of these have the tritone resolving to the ^1 and ^3 of the Cmaj7. You can even use a B7. A 7th chord built on the ^7 of a major key is sometimes used in chord progressions. The tritone of B7, D# and A, resolves to the 3rd and 5th of the C chord. “Meditation” immediately comes to mind. The first 3 chords are: Cmaj7-B7-Cmaj7.

There are other non-diatonic and colorful options, for example replacing the entire final 2-5 with another, like the sub 2-5, Abm7-Db7 or a 2-5 based on a bVII7, Fm7-Bb7.

In the end I wouldn’t concern myself too much with “theoretically correct”, a lot of jazz harmony doesn’t bother. Just go with something that sounds good to you but every option I offered has some basis in theory.

Answer 3

The transition G7 -> Am is common and makes for easy voice leading; going to Am7 is a bit more difficult as the previous C chord makes Am7 would a lot like C with an added sixth. Going back from E may be accomplished by using the note E as a pivot (a similar strategy to that in "Delilah_"). A moving bass line can smooth out some things.

I got a version to work, but Stack Exchange doesn't allow the posting of pdfs.

Answer 4

Like other responders, I find the major-to-minor transition to be the easier one to "solve". The only additional suggestion I can offer is that you keep the G7 and insert a passing G♯dim7 before the Am7:

Cmaj7 | Cmaj7 | Dm7 | G7 G♯dim7 | Am7 …

The G♯dim7 differs from the G7 by only one tone, and functions like a rootless E7♭9.

The minor-to-major, on the other hand, is trickier. I don't have a great theoretical basis for this (and will happily accept one) but I like how it sounds. It also uses a passing chord, but moving by whole steps downward rather than half steps up:

Am7 | Am7 | Bmin7♭5 | E7 Dm6 | Cmaj7 ...

I guess the Dm6 is just an inversion of the Bmin7♭5, but it could also be considered to function as a rootless G9 so it has some similarity to my other idea.

Hear it.