Bodhisattva turn around

[SwampAsh]

The theory behind the turn around to the Steely Dan song Bodhisattva confuses me. The song starts by creating a strong sense of being in the key of G then uses a common blues riff on G and C which I would consider to be the I and IV respectively. Then on the turn around we go to an Eb major, A7b13b9, Dm7, F13 which I'm assuming is some kind of ii V ii V using substitutions but I just can't see it. Especially this Eb chord. How does this relate to G? I suppose it really could be a Bb13 but that doesn't help much or it could be a G#11 Augmented but I don't think so. It could be a key modulation but to what, Bb? I just am not seeing the light. Any thoughts?

Thanks

[SwampAsh]

Okay what about this...

The EbM7 is really a weird E1/2dim. Giving it a bottom note a tritone
away the A7b9b13 which makes for a smoother bass movement. Then the A
to the Dm7 is a II v then resolves to the F13 which is really an
altered G chord. Like a G9/11. Thart would in essence give us a III VI
II v resolving to I. Using the Dm7 to G7 looks like a ii V to the C
chord. So maybe we are talking about a little ambiguity related to key
which is possible since the G7 is the V of C.

I know I'm talking to myself! Please untie this straight jacket so I can scratch my nose! I'll be good I promise.

[SwampAsh]

Okay here I am talking to myself again but I think I'm onto something. Nothing really seems to make sense until you start thinking in terms of G minor. Eb major 7th fits diatonically with G minor and the F13 Is really a G9 11 when you add a G pedal tone.

[DesiSerna]

Good question and great tune. I'm not sure what's happening in the song exactly, and I can't find my Steely Dan tab book that I used to have. But I think you're on the right track. The G to F chord riff in the verse is basically a V IV progression in C. The harmonized guitar melody is a great example of playing in Mixolydian mode. The C to Bb is a V IV in F key change. The next part is a key change to G minor. You can play Bb major scale patterns over it. There's definitely something more to it, but this is the best I can do at the moment.