bVII7 in functional harmony

[christianm77]

Your response is totally relevant to the second half of the bridge (and to the "A" of the tune).

However, I refer to the first half of the bridge. The beginning of the bridge is a minor II-V to IIm, and the chord I'm talking about is a I7 (in place of the IIIm7b5 in a vanilla minor II-V).

I'm fine with considering that I7 an entity by itself (in line with your answer that IIm is "a centre that eventually turns into the IIm7 subdominant"). The fact that it's a 7 chord doesn't bug me, the same way that II7, VI7 and III7 often work as entities using a whole 2-measure chunk.

That way, the bridge would be: two measures of I7, followed by a "minor II-V to IIm" (which happen to feature the very same I7 chord) using another two measures, resolving to IIm.

Does that make sense?

I don't think I understand the question.

How would I categorise I7? Similar to VI7. A moving chord that goes to Gm/Bb.

In fact as you say I7= iii7b5 so, we have a long minor II-V into Gm if you like, which is neat, hadn't thought of that.

F7 | % | % | D7b9 | Gm |

becomes
Am7b5 | % | % | D7b9 | Gm

In any case no-one likes playing on m7b5 chord apart from dweebs, so most of our time in bebop land is spent playing F7. We might tangentially bother with D7 if we want to in some way, and end up in Gm/Bb land over the relevant chord. So we get:

F7 | % | % | % | (gubbins) --> | Gm |
(As Am7b5 = F7)

Or if you prefer

F7 --> Bb

So the whole thing is a backdoor to Gm or a V-I into Bb. This approach relies on you having lots of interesting things to play on F7, which shouldn't be a problem for a bop head. You can also use Cm ideas, because Cm6 = Am7b5.

Cm | % | % | (gubbins)--> | Gm

Which again, you know blends the traditional subdominant and dominant worlds (that is to say II V, choose one or both.)

Alternatively we can add more movement by walking down from F7 to D7 trad style:

F7 E7 Eb7 D7
Or bop style

Cm F7 | Bm E7 | Bbm7 D7 | Am7 D7 |

Which is a common move IIRC.

Does that answer your question?

[christianm77]

BTW, all of this harmony apart from the walk down chords belongs to the Gm key (and the three scales we use traditionally, natural, harmonic and melodic)

The reason I wouldn't recommend simply playing Gm is because the emphasis is important. Playing on Cm6 and F7 (or if you really must Am7b5) will give you a better emphasis for expressing moving harmony. If you simply play Gm, you run the risk of sounding like you are just sitting on that chord.

For example, if I play F7, I'll emphasise F A C Eb, which (especially Eb) are the less 'settled' notes of Gm. OTOH if I play Cm6/Am7b5 I'll emphasise A C Eb G, which G obviously aside, have a more 'restless' quality than the Gm triad chord tones.

BTW, you could also use Cm7, or Ebmaj7(#11)

[alez]

Does that answer your question?

Absolutely yes, thanks so much for this. Your post has the answer to my question plus a lot of additional food for thought.

[MarkRhodes]

I associate that sound with Chicago bluesman, Magic Sam - blues progressions where the I is minor and the IV and V are both major. Charles Brown's "Black Night" is another tune based on those moves:

"All Your Love":

"Black Night":

I love Magic Sam and that sound influenced me greatly. Though I tend to drop the IV altogether except for the turnaround. (8 measures of i plus a turnaround)