Keb Mo theory question

I’ve been working on this great blues track by Keb mo. The main body of the song is a typical I IV V in the key of E and I’ve got the verse sections down quite well.
However, during the bridge the key appears to change to A minor and it’s quite a lovely sounding jazz style progression.

A min 7: 4 beats
D7 :2 beats
D9: 2 beats
G Maj 7: 8 beats

G min 7: 4 beats
C9: 2 beats
C7: 2 beats
F Maj 7 4 beats
I can see the use of secondary dominant chords in there to resolve to G Maj7 and B7
But I was wondering if any theoryites out there could explain this in more detail?
I don’t understand the use of the G min 7 chord?
This topic may of been better off placed elsewhere so apologies if it has to be moved.


Sorry, can’t help, but I love Keb Mo.

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There’s modulation happening to alternate keys perhaps and I can’t analyze that with any certainty at all but, the last B7 you wrote does not seem to be functioning as a secondary dominant as that would lead next to an E maj or min chord so it’s a “natural” dom in E.

Anyhow, the Gmin7 is an interesting tonal center change up to the tune as you say. It sounds good so ….

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Hi Brian
Yes the B7 Chord is the Dominant in E major which gets him nicely back to the verse.
The secondary dominant is F major 7 and the dominant of that is C7
So my understanding is the C7 F Maj 7 B7 progression is leading nicely back to the E major tonic but I wasn’t aware Maj 7 chords functioned in this way and the The use of G minor 7 is a little puzzling.
It all sounds great but I’m just interested in how it all fits together.
In fact the secondary dominant should be F#7 so that’s even more perplexing! :woozy_face:

It is tasty. I haven’t had time to look at modulations, key changes, chord functions.
I have the 9th chords as 7(b9) chords.
The progression I see / hear is:

Major 7th chords are not dominant
(they arise from the I and IV in a key). Only the V in a key gives rise to a dominant which can - in a different setting - act as a secondary dominant.
The dominant chords here are the D7 and D7(b9) plus the C7 and C7(b9).

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The main body of the song is ii V I in G a very common jazz progression.
I’m at work so don’t have time to go thought the video with my guitar to see what chord he’s playing.


Thanks for your analysis Richard.
I’m sure you’re right. I wil change the progression accordingly. Although the 9 chords do sound ok.
It’s a very interesting and beautiful sounding break from the main body of the song.
I’m sure Keb has used a formula he’s come across before to get this sound but I’m perplexed as to how you would think of an F Maj 7 B7 progression?

I think that’s right Rick!
So I’m guessing the bridge involves 2 key changes?
2 5 1 in G then 2 5 1 in F?
All seems to fit together seemlessly.


Just had a chance to really watched the video and I have to correct myself. I was going off the chord you posed and your right the main Body of the song is a I V IV in E.
But the Bridge is as I stated in my above post. Glad you got it worked out Cool Song Thanks for posting it.

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Definitely that.


Thanks Richard
And the F Maj J has a lovely sound back to B7 even though there doesn’t appear to be any real relationship between the 2 chords.

Thanks Rick
I’m really getting this one down.

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ii V I, le jazz. Of course !

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Late night thoughts … should be getting ready for sleep. This has popped back into my head.
I’m not a jazzer (playing or listening) so my jazz theory knowledge isn’t the best.

Take the root notes.

A → D → G → C → F

We have descending 5ths. Think of the circle of fifths as representing notes only, not chords, and we have an anticlockwise movement from A to F. If we include the E chord of the main 12-bar itself, which precedes the Am7, then we have six descending 5ths in the root notes.

E → A → D → G → C → F

From F there is a leap to the direct opposite position on the circle of fifths, to a chord with B as its root. This is a tritone leap. I’m not seeing this as a tritone substitution as it is Fmaj7 to B7 not F7 to B7. I will explore some more on that aspect.

The song I Will Survive contains a progression of chords whose root notes follow descending 5ths in like manner …
Am → Dm → G → Cmaj7 → Fmaj7 → Bm7b5 → Esus4 → E

There is a phenomenon called the circle of fifths progression. This bridge uses it and does in a way that the chord choices form a descending series of ii, V, I patterns too.


Nicely done. I have a foggy awareness of this progressive movement of 5ths. I think Giant Steps and lots of other examples out there. Interesting to see your “step” wise approach to the analysis by starting with root note tracking, regardless of flavour (m/maj/7/dim) of the chords in question.

Thanks for this Richard. I will have an in depth look once I’m home this afternoon.
In th meantime I was thinking this through last night as well.
There appears to be a strong voice leading element to the F Maj 7 to B7 movement.

F Maj7: F A C E
B7: B D# F# A
F to F# A stays where it is, C to B and E to D#

Also I was thinking F is the Dominant chord in B Locrian? So maybe it could explained that way but it’s probably a bit of a stretch…

Further …

Fmaj7 to B7.

Yes, the roots follow a tritone movement. This is an essential for tritone substitution. It does not have dominant 7 (or extension of) moving to dominant 7. A feature of dominant 7 chords is that they contain an internal (unstable) tritone interval between 3rd and b7th. With a tritone substition, the root notes move to a root a tritone away and the internal tritone is maintained but inverted. This sometimes requires the notes to be named using enharmonic equivalents.
If that F chord was F7 and it was moving to B7 that would be a clear tritone substitution.

Instead, this has an Fmaj7 moving to B7. The roots have a tritone movement but Fmaj7 contains no tritone within it, it is not a dominant and it is not functioning as a dominant.

There is strong voice leading throughout. Virtually all chords contain common notes with static chord tones as the chord change happens and mostly semitone movements up or down between other chord tones. Plus the descending 5ths in the root notes and the tritone shift from F to B already discussed.

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I forgot to add …

Strictly speaking, according to theoretical principle, the Fmaj7 to B7 would not be considered a tritone substitution. Unless you take an elastic and relaxed view on these things. Unless you allow that the term can apply to any chord change - no matter the quality of the chords, whether dominant or other - whose root notes are at an interval of a tritone.

Amazing work Richard!
Thank you for your input on this.
Very much appreciated

And I was recently looking at a blues composition that uses the #I dim7 to lead to the IV chord and the #IV dim 7 to lead back to the I chord.
Just looking on my guitar it looks as though they contain the tritone subs you are referring to to add some flavour?
Eg: blues in E
Either Bb7 or F dim7 could be used as a tritone substitution?