In Since I've Been Loving You I'm having a hard time figuring out what goes on during the turnaround. I transcribed the chords and this is what I got, G minor, Ab/Eb, F minor, C/Eb, G7/D, C minor, Eb/Bb, D7, Db major 7. So I want to know what is going on theory wise. The non diatonic chords are G7/D, D7, and Db Major 7. So does G7 come from the parallel major, D7 come from C Dorian, and Db major 7 come from C Phrygian? So it's going v, VI, iv, i, V7, i, III, II7, bIImajor7. Does the turn around resemble any popular chord progression like I, IV, V or ii, V, I?
No need for modes on this one mate.

|Cm7             |Fm7             |Cm7             |Cm7             |
|Fm7             |Fm7             |Cm7             |Cm7             |
|Gm7             |A♭Maj7   Fm7   |Cm/E♭ G/D Cm E♭|D7      D♭Maj7  |

The A♭Maj7 is a diatonic substitution for the Fm7 and so far it's fairly straight forward 12 bar blues. (The whole thing is just a very nice elaboration of the 12 bar blues but you knew that already).

The C G C E♭is in a way a an elaboration of the tonic chord i V i ♭III, you could look at the V and ♭III here as kinds of substitutes against the i chord that work to prevent us from settling on the i. It really is a harmonic distraction though the real trick here is happening in the bass which is creating expectations of things to come and setting us up for the final turnaround.

So looking at the bass things move in even quarter steps much like the harmony with the first three bass notes starting on E♭ then down to D then down to the root C. It returns back to the E♭ and it's a total set up.

The final turnaround starts with a D7 which is a II7. It is common enough to find a II7 in this part of the 12 bar blues setting up a II7 V7 I turnaround. But here we have been set up in the previous bar with a descending line to expect E♭ D C. Only this time our expectation is thwarted as the D is held twice as long and then instead of moving to the C it moves down a half a step to the D♭ for another half measure which really drags out that tension before being released back into the Cm7 at the start of the next section.

In this way the D♭ acts like a tritone substitution. Only it's not a full fledged tritone substitution. It has the same chromatic root movement as a II7 ♭II7 i, but it's not a dominant 7th chord and doesn't contain the tritone from the V7. Instead it's a major seven chord.

The ♭7 of the D7 chord is a C and is prominant in the lick played over that D bass. The D♭Maj7 moves the triad down a half step but keeps the lick that is based around that C in the same place which is why we get the Maj7.

It's as though Page knew he was really dragging us out with this turnaround and is teasing us with this lick that is bending up away from and down to that C giving us a taste of the tonic resolution that we are longing for but not enough to really satisfy. And when the Cm finally comes it feels so right.

Great song.

This is just the way I see it, anyway.

EDIT: Oh and if I were to liken it to a more standard progression I would view it as an elaboration of a 12 bar blues with a II7 V7 turnaround.
|i   |iv  |i   |i   | 
|iv  |iv  |i    |i   |
|v   |iv  |i   |II7 V7|
with a bunch of substitutions in the last three bars
in bar 10- ♭VI for iv making it |♭VI vi|
in bar 11 V for i and ♭III for i making it |i V i ♭III|
in bar 12 ♭II for V7 giving us |II ♭II|
or something like that.
Last edited by 20Tigers at Sep 16, 2010,
Ok so let me see if I got this. The G minor is just the v chord which is usually the first chord in a standard blues turnaround. The Ab major and F minor are closely related, and can be substituted for each other, so it's like playing a iv chord which is the second chord in a standard blue turnaround. This next part I'm kind of confused on. So he is playing basically the i chord by playing the chords of the notes in C minor? All that I understand is that that whole part can be taken as a i chord. The last part is basically a v chord(the last chord in a standard blues turnaround), and the Db major 7 is a tritone substitution, even though it is a bIImajor 7 instead of bII7. So the only part's I'm still confused about is the one that I said earlier and I'm still not getting where the D7 comes from. Thank you so much, very in depth analysis and a good one too.
The D7 is simply a secondary dominant, V7/V. It's a pretty basic turnaround. You have predominant, dominant, tonic. Just like a IV V I or a ii V I, just with a bit of substitution.

The D7 is the predominant (leads you into the dominant), Dbmaj7 is the dominant (leads you into the tonic), and Cm is obviously the tonic.
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