Jerry Donahue & diminshed substitutions

[jhumber]

Hey all,

I recently picked up a copy of Jerry Donahue's Telemaster Guitar book - which is excellent.

There are two open-string licks in there that are causing me to head-scratch a little. The licks outline the following chord progressions....

1) Ddim7 - A7 - D
2) C#dim7 - D7 - G

Now, both of these end with a V-I resolution. My question is: in what capacity are the dimished chords being used here? Are they substitutes for ii chords (which would of course imply an altogether more common ii-V-I)?

Both licks sound great, but I'd like to understand why each dimished chord was chosen.

Cheers
Jordan

[sausagefingers]

That's interesting. In the first example, if you are resolving to D the ii would be E-7:

E G B D

The b5 of that is Bb7:

Bb D F Ab

which shares notes with Jerry's Ddim:

D F Ab C

Sounds like a version of b5 sub. I recommend gennation's pages (Mike Dodge) regarding these substitutions--maybe he will chime in here.

[willhutch]

So the single-note runs in the book outline these chords. Are these chords being superimposed over a chord, or chords, played by the rhythm section?If so, what what chords are being played in the background. Knowing this may help understand what's happening.

[jhumber]

These chords are being outlined by the single note runs.
(There is no rhythm section - its a guitar only recording of the lick).

[Lammy]

It is like a V7b9/V7 to V7 to I. So it is a V-I (E to A) then a V-I (A to D) again

D dim7 outlines a E7b9 omitting the E

Same concept for the other lick, The C# dim7 outlines an A7b9 chord.

C#dim7 = Edim7/Gdim7/Bbdim7
Ddim7 = Fdim7/G#dim7/Bdim7

Easy peasy, V-I baby. Using this instead of a ii creates more tension and leads into the V chord more powerfully.

[JonR]

As Lammy says, both dim7s are substitutes for II7 chords - secondary dominants, instead of a diatonic ii (m7) chord.

Try playing E7(b9)-A7-D for the first one and A7(b9)-D7-G for the second - compare the sound.

[medrawt]

The way it's written or notated might be confusing; both of these licks have the same harmonic information. Everyone else has given pretty much the right answer, but if it helps to be more explicit (and sorry if you already know this stuff):

D diminished 7 is the same as Fdim7, Ab dim7, and Bdim7 - the same notes for each chord. And a dim7 chord is (often) a substitute for the dominant 7 chord down a third - i.e., if we have a dim7 chord that could start from D, F, Ab, or B, then it could be subbing for Bb7, Db7, E7, or G7. E7 is the "right" call, and you've got II7-V7-I, a common alteration on ii7-V7-I.

The C#dim7 in the second progression is the same, it's just notated in a different inversion - C#dim7 is a sub for A7, ergo A7-D7-G, II7-V7-I. If the two examples had their harmonies written the same way, it would've been called Gdim7.

And sausagefingers is right that this has to do with tritone subs - once you change E-7 to E7, you can also change it to Bb7.

[Lammy]

JonR,
technically the II7 term is incorrect as it implies the chord is a non functional dominant which in this case is not true.. It would be called the V7/V7 (the dominant chord of the dominant chord, example= in Key of C, the dominant chord of C is G7, and the dominant chord of G is D7) , secondary dominants! semantics.

[kimock]

Originally Posted by medrawt

C#dim7 is a sub for A7, ergo A7-D7-G, II7-V7-I. If the two examples had their harmonies written the same way, it would've been called Gdim7.

If you're in the key of G, why wouldn't you assume that the natural notes, G and E belong to the subdominant?
It's closer. . .

[JonR]

Originally Posted by kimock

If you're in the key of G, why wouldn't you assume that the natural notes, G and E belong to the subdominant?
It's closer. . .

I don't know about "closer". G and E also belong to Em and Am, and are only half the notes in the dim7 chord anyway.
C#dim7 only contains 2 notes from C major. It contains 3 from A7. IOW, half of C#dim7 = 2/3 of C. Not that close. 3/4 of C#dim7 = 3/4 of A7 - much closer.

However, C#dim7 is as close to C7 as it is to A7 - that's true. So the question ought to be - why not consider C#dim7 to be standing for C7, not A7? (I won't argue for either Eb7 or F#7 as they are a stage or two further removed from the G major key.)

I suppose a lot depends on voicing, but I find C#dim7-D7 (however they're voiced) sounds a like more like A7-D7 than it sounds like C7-D7.
I'm not sure why that would be - I guess because of the C# leading tone.
Out of the two chromatic notes in C#dim7, C# sounds more significant than Bb - I don't know why.
Chromatic notes should ideally resolve a half-step either way. C# can go to either C or D (and does both in the move to D7); Bb can go to either A or B (goes to A in D7).
When we replace C#dim7 with either A7 or C7, we lose one of those chromatic moves. Personally I think the A7 sub sounds better - for some reason it sounds (in this cadence) more like C#dim7 than C7 does - although I really don't know why.
I don't want to invoke pre-existing theoretical concepts to explain it: "oh A7 works better because it's a secondary dominant, and C7 isn't". Why would that make it better?

There is the other common use of C#dim7 in key of G, and that's to go from a C (or C7) chord to G/D. Happens all the time in bar 6 of a jazz blues. In that case, one can well argue it's a variation on the preceding C7 chord, providing a rising bass line to the 5th of G. Not a secondary dominant there, then!

I think it has to come down to the chords either side, and the kind of chord changes we're used to hearing. We've all heard countless songs in G where D or D7 is preceded by its secondary dominant, A(7).
But then, I can hear you saying, we've also heard countless songs in G where D(7) is preceded by C7. What's the difference?
In short, I dunno! (Damn, this IS a good question...)

[JonR]

Originally Posted by Lammy

JonR,
technically the II7 term is incorrect as it implies the chord is a non functional dominant which in this case is not true.. It would be called the V7/V7 (the dominant chord of the dominant chord, example= in Key of C, the dominant chord of C is G7, and the dominant chord of G is D7) , secondary dominants! semantics.

Thanks Lammy. I'm aware of all that, I just used "II7" as shorthand, regarding the secondary dominant issue as given. But you're right of course!
(What do you think of kimock's argument above? Or at least the way I've extrapolated it? I've a feeling I'm missing something, but damned if I can put my finger on it...)

[kimock]

Originally Posted by JonR

I don't know about "closer". G and E also belong to Em and Am, and are only half the notes in the dim7 chord anyway.
C#dim7 only contains 2 notes from C major. It contains 3 from A7. IOW, half of C#dim7 = 2/3 of C. Not that close. 3/4 of C#dim7 = 3/4 of A7 - much closer.

However, C#dim7 is as close to C7 as it is to A7 - that's true. So the question ought to be - why not consider C#dim7 to be standing for C7, not A7? (I won't argue for either Eb7 or F#7 as they are a stage or two further removed from the G major key.)

I suppose a lot depends on voicing, but I find C#dim7-D7 (however they're voiced) sounds a like more like A7-D7 than it sounds like C7-D7.
I'm not sure why that would be - I guess because of the C# leading tone.
Out of the two chromatic notes in C#dim7, C# sounds more significant than Bb - I don't know why.
Chromatic notes should ideally resolve a half-step either way. C# can go to either C or D (and does both in the move to D7); Bb can go to either A or B (goes to A in D7).
When we replace C#dim7 with either A7 or C7, we lose one of those chromatic moves. Personally I think the A7 sub sounds better - for some reason it sounds (in this cadence) more like C#dim7 than C7 does - although I really don't know why.
I don't want to invoke pre-existing theoretical concepts to explain it: "oh A7 works better because it's a secondary dominant, and C7 isn't". Why would that make it better?

There is the other common use of C#dim7 in key of G, and that's to go from a C (or C7) chord to G/D. Happens all the time in bar 6 of a jazz blues. In that case, one can well argue it's a variation on the preceding C7 chord, providing a rising bass line to the 5th of G. Not a secondary dominant there, then!

I think it has to come down to the chords either side, and the kind of chord changes we're used to hearing. We've all heard countless songs in G where D or D7 is preceded by its secondary dominant, A(7).
But then, I can hear you saying, we've also heard countless songs in G where D(7) is preceded by C7. What's the difference?
In short, I dunno! (Damn, this IS a good question...)

Yeah, I don't know the answer to this either, maybe has to do with where the melody is. . .
When I said closer, I meant closer to the Tonic, as in down one fifth from G as opposed to up two fifths.
Or as chord tones E and G being a 3rd and 5th as opposed to a 5th and 7th. Just closer to G.
I don't disagree with the II V I interpretation, but it seems to be the consenus in spite of the fact that IV V I is a less distant relationship, and I couldn't figure out from what little info was provided why II V got the nod over IV V.

gotta run!!

peace

[JonR]

Originally Posted by kimock

I don't disagree with the II V I interpretation, but it seems to be the consenus in spite of the fact that IV V I is a less distant relationship, and I couldn't figure out from what little info was provided why II V got the nod over IV V.

Tradition?
Dim7s in that position are always assumed to be standing for the V of the following chord.
They connect with the vii chord of harmonic minor. So C#dim7 is the diatonic vii chord in D harmonic minor. As such, its natural target is Dm.
And dim7s can easily be transplanted into a major key, given a major target tonic.
So that becomes a habit, to see C#dim7-D as standing for A7(b9)-D.

That's even tho, aurally, we might interpret C#dim7 as Edim7, Gdim7 or A#dim7, meaning it could have 3 different targets, and be standing for 3 other dom7s. The symmetry meaning the resolution can go 4 ways - meaning in turn that the dom7s might be able to go 4 ways?

Although, if we try this, it doesn't quite work equally well: Compare the following:
1. A7-D
2. C7-D
3. Eb7-D
4. F#7-D

#3 is the tritone sub, commonly accepted in jazz (and in classical, but only as an augmented 6th going to V).
#2 is also seen fairly often in jazz.
But #4 is rare. It kind of works, but in a strange way. (Maybe down to the relative minor relationship, F#7-Bm.)

Certainly, all 4 have different sounds, not really equivalent, in the way the dim7s are.

[kimock]

Originally Posted by JonR

I've a feeling I'm missing something, but damned if I can put my finger on it...)

Me too, something about the simultaneous ambiguity of the quadrisection of the octave, the functional "Problem of II", and treating the dim as dom is screwed up. Maybe Henry the Horse knows. . .

peace

[JonR]

Originally Posted by kimock

Me too, something about the simultaneous ambiguity of the quadrisection of the octave, the functional "Problem of II", and treating the dim as dom is screwed up.

I wouldn't say screwed up, necessarily. I think it comes back to that harmonic minor vii chord, that's where the logic lies - although the association is no doubt theoretical, not some vague primal subconscious auditory one

Originally Posted by kimock

Maybe Henry the Horse knows. . .

If anyone does, he does.

Come on henry, wake up...


(Sorry, couldn't resist that one )