How are diminished chords used to connect the I chord and the II chord?

[montorgueli]

for example: C maj7-C#dim7-Dm7-G7, would be a very typical progression. But I don't know exactly how that works from a theory standpoint. Is it because of the half step motion between the chord tones of the dim7 and the m7? (but not all the chord tones are moving by half step... so...?)

and, according to this book im looking at (theory and harmony for the contemporary musician, if you're wondering), another acceptable progression would be... Cmaj7-Cdim7-Dm7-G7. Why is that? How do you account for the transitions between the maj7 the dim 7 and the min7?

and apparently dim7 chords may also be used to connect the IV to the V, like here

F6-Abdim7-G7.

that seems to work because there's three common tones between the dim7 chord and the G7, but how do you account for the transition between the F6 and the dim7?

[Jazzaluk]

Diminished chords are very ambiguous, so they can be employed in many ways, as passing chords and as substitutes for dominants. Your first example (C#dim7), can be viewed as either a passing chord to create chromatic movement to Dm7, or as a substitute for the secondary dominant A7, where C#dim7 functions as A7b9 (no root).

In the second example, I would view the Abdim7 as simply a substitute for G7 with the b9 in the bass (or a Db7b9 tritone sub of G7). I really depends on the context of the tune.

Overall, I wouldn't get to analytical about the function of diminished chords since they generally function as passing chords or dominants and represent some chomatic movement between chords that is specific to the tune. I suggest looking at the melody and bass line to see where the chromatic movement was intended or sounds best, experiment with a few inversions and trust your ear.

[m78w]

There are three "types" of diminished 7th chords that are commonly used in jazz:

1) Tonic Diminished, or Diminished maj7. This is when a Imaj7 chord is substituted with a Idimmaj7 chord.

So like the first four bars of Out of Nowhere is:

Gmaj7/Gmaj7/Bbm7/Eb7

and it becomes

Gdimmaj/ Gdimmaj/ Bbm/ Eb7

The scale for that type of diminished chord is the whole half diminished scale starting on G.

G A Bb C Db Eb E F#

2) Tonic Diminished or 7b9 chords

This is where a 7th chord is substituted with a diminished 7th chord a half step up from the root to imply a 7b9 chord.

So C7 becomes C#dim7, which is like C7b9/C#.

3) Passing diminished, this is where a diminished chord is placed between two chords a tone apart.

So a harmonized C major scale would be:

Cmaj7 Dm7 Em7 Fmaj7 G7 Am7 Bm7b5

and with the passing diminished chords it becomes:

Cmaj7 C#dim7 Dm7 D#dim7 Em7 Fmaj7 F#dim7 G7 G#dim7 Am7 A#dim7 Bm7b5.

So you can use any or all of those chords in your comping.

A good example is the first 4 bars of rhythm changes:

Bbmaj7 G7b9/Cm7 F7/ Dm7 G7/ Cm7 F7/

becomes

Bbmaj7 Bdim7/ Cm7 C#dim7/ Dm7 C#dim7/ Cm7 Bdim7/
Bbmaj7 Bb7/ Ebmaj7 Edim7/ Bbmaj7/F G7b9/ Cm7 F7/


Hope that helps,
MW

[lkmuller]

Matt, can you spell out the Gdimmaj for me? It's a new one for me.

Thanks

[m78w]

Sure,
It's G Bb Db F#, it's sometimes refered to as the "Jim Hall" chord because he uses it all the time.

The voicing Jim uses is spelled G Db F# Bb, you'll also see this voicing used as an A13(b9) chord with no root. A chord that Herbie Hancock used all the time in his comping especially on those classic Wayne Shorter tunes like Infant Eyes and Pee Wee for example.
The rule for diminished chords is that you can add any note(s) one tone higher than any note in the chord.

So for G diminished 7,

G Bb Db E

can become any of these

A Bb Db E

G C Db E

G Bb Eb E

G Bb Db F#

or any combination of one or more tones added above the chord tones.

Hope that helps,
MW

[lkmuller]

OK, thanks, the 13b9 chord I'm familiar with. I use it as a sub for a VI chord a lot. The first voicing you mentioned (G Bb Db F#), right off the top of my head because I don't have my guitar in hand just yet, I guess I would've called a Gmin/maj7#11, or a Gmin/maj7b5. I'm really not sure if I would've been correct theory-wise. It sure makes more sense the way you labeled it, as a Gdimmaj.

Thanks much. I love talking and learning chord theory.

[m78w]

The minmaj7 is a great sub if you have 2 bars or more of a maj7 chord. It really gives it a different sound rather than just run up and down major scale stuff.

Check out tunes like Lady Bird:

Cmaj7/Cmaj7/Fm7/Bb7

becomes

Cdimmaj7/Cdimmaj7/Fm7/Bb7

or Green Dolphin Street

Cmaj7/Cmaj7/Ebmaj7/Ebmaj7/Dmaj7/Dbma7/Cmaj7/Cmaj7

Becomes

Cdimmaj7/Cdimmaj7/Ebmaj7/Ebmaj7/Dmaj7/Dbmaj7/Cdimmaj7/Cdimmaj7

It's an easy way to spice up your maj7 chords.

MW

[montorgueli]

taking into account the responses here and on Yahoo Answers, I think I have everything regarding diminished7th chord substitution all cleared up. Thanks for your time and responses, guys

[rintincop]

Good job, Jim.

I'll further add that the G dimmaj chord (reharm) works with every note in the melody except the 3rd or 5th of the chord. So when 3 or 7 are in the melody I use Jim's case 2 (rootless V7b9/I) or think Vii dim7/I (which is the same thing).

[jordanklemons]

Playing off what Matt was saying...

Using the dimMaj7 chord as the tonic can work great. So can moving between that tonic dim chord and the Maj root chord. Subbing in the dimMaj7 in place of the Maj7 chord when it's held out for 2 bars works, but we can create some great movement by moving between the 2 chords dim7 -> IMaj7. And we can use the dimMaj7 or just the fully diminished for that movement. Because the point is just tension and movement.

So over Lady Bird, we could do

CMaj7/CMaj7/F-7/Bb7

Or like Matt pointed out, we can do

CdimMaj7/CdimMaj7/F-7/Bb7

Or we can put the two together and play something like

Cdim7/CMaj7/F-7/Bb7

It can be used to great effect when we're creating some kind of melodic comping or voice leading.

Cdim7
X3424X
CMaj7
X3545X
F-7
X8686X
Bb7#5
6X677X
Cadd2
X7.10.7.8X

Notice the ascending chromatic line in the top voice.

Of course, all of these options work when improvising, comping, or playing solo. We probably wouldn't want to use the dim7 option, or the particular shapes I wrote out, when comping behind the melody, as the first melody note is the natural 5th. You might be able to pull it off. But it's probably better to focus on really learning to properly harmonize the melody notes when learning a tune... and maybe spend those 2 measures creating movement from the CMaj7 chord to the F-7 to come.

[jordanklemons]

And as for the OP, my view on diminished chords is that they can either resolve to the same root note, the root note a half step away, or a root note a whole step away.

And since the diminished chords repeat every minor 3rd (every 3 frets), and the diminished chords can resolve to any of the chords within that 3 fret stretch... the basically means we can use them to pass between any sets of chords. Be it the I and the ii, the IV and V, etc.

As for your particular question regarding the CMaj7-Cdim7-Dmin7-G7

You can either think of that as the Cdim7 resolving up a whole step, or as an inversion of the Ebdim7 (these 2 chords are made of the exact same notes) resolving down a half step.

Check out these guide tone lines, the voice leading between these chords is simply beautiful...

CMaj7
X35X5X
Cdim7
X34X4X
D-7
X53X3X
G7 (13 and #11)
3X2X2X

I left out a bunch of notes so you could see and hear the 2 descending chromatic lines hidden inside this progression. I left the chord root notes in just to help visualize the shapes. It's probably worth learning to play this with and without the root notes.

[gggomez]

wow there is a month of learning here. thanks guys, I have never really understood diminished this really helps.

[jordanklemons]

Yeah, they're kind of squirly triple G. They can kind of go anywhere. I'm still trying to wrap my head around them completely.

I used to tend to use them just mostly as a passing chord between two chords a whole step apart. But a few years ago, I realized I was being very disrespectful to (or with) them. I was just relying on the fact that they created tension to make them work. But there's some really subtle issues that arise that I started noticing. And it makes such a world of difference in my ear for how musical they can be.

For instance, in Bye Bye Blackbird, I would sit on the F tonic for a while (maybe with some 2 5s or something for movement), and then in bar 5 (I think) I would use an F#dim7 to resolve me up to the G- where I'd hover for the next few measures. But then it dawned on me that I was using an F#dim7 chord to harmonize a G note. It was tension moving to resolution, and it was short lived... so it sort of worked. But really not harmonious at all. Did not properly accompany the melody. But when I started treated that chord as an Abdim7 chord? Aaaaaahhhh, lovely. It totally embraces that G note in the melody. And it creates a fantastic resolution down a half step to the G-.

They're tricky like that.

[jordanklemons]

Which - not to confuse the question from the OP - but that's another option for using a dim7 chord to get from the I to the ii.

[gggomez]

is it derailing the thread to ask for some simple discussion to use in a blues?

eg I have been practicing (not enough) using over the v chord and avoiding the root (that is in a Bb blues play fdim over the f7 but avoid f (source Joseph Alexander)?

[jordanklemons]

Can you be more specific about how you're using it? My initial instinct is that it wouldn't work very well, as the Fdim7 has the 3rd and 7th of the Bb7 chord in it... so it's effectively going to sound like a Bb7b9... no?

But I might not be understanding exactly how you're talking about using it. Can you go more into detail? If the thread doesn't mind.

[nick1994]

I think he means playing a #9 and #11 over an F7

[gggomez]

My understanding is the concept is that this is the chord to get a bit excited on, create some tension.

[JonR]

My understanding is the concept is that this is the chord to get a bit excited on, create some tension.

If you're talking about the V7 chord (F7 in a Bb tune), yes.
But the point of the tension is to resolve on to the tonic - Bb in this case, which will usually be the following chord.
That's the purpose of all the common alterations on (and subs for) a V7 chord.
Sometimes those alterations suggest a diminished scale, sometimes they suggest the "altered" scale, sometimes something else. But it's always about the linear voice-leading from chord to chord, not the scale's whole effect on the chord itself.
Eg, you might take the F7 and flatten the C. That would be to lead down by half-step to Bb.
Or you might raise the C to C#. That would be to lead up to D on the Bb.
Or you could add a b9 (Gb). That could either go down to F on the Bb, or go up to the 6th (G) on the Bb. And it might follow on from a G on a previous Cm7 chord.
The #9 meanwhile (G#) could also go down to G on the Bb, or (less likely) up to A, the maj7.
Other extensions on the F7 could be shared tones with the Bb, such as a 13th (D) - or even a sus4 (Bb), although that could well go down to the maj7 on Bb.

To get back to the thread (although it was started 8 years ago!!, m78w pretty much covered the three kinds of dim7 chord. I might simplify it as follows.

1. What he called "tonic diminished" is traditionally (classically) known as the common-tone diminished. This is where the root of the dim7 is the same as the root of the following chord (and often of the preceding one too).
In fact, because dim7s are symmetrical, we can say where any note of the dim7 is the same as the root of the following chord.
It doesn't need a maj7 on it - it could retain its bb7, which is equivalent to the 6th of the following chord. Either way it shares that note (as well as the root) with the next chord. So you could have C6 > Cdim7 > C6, or Cmaj7 > Cdim(maj7) > Cmaj7.
A > A > A
G > Gb > G
E > Eb > E
C > C > C
or
B > B > B
G > Gb > G
E > Eb > E
C > C > C

2. The leading tone chord. You often see this referred to this as a sub for a 7b9, but in fact it's a chord in its own right, derived from the vii degree (leading tone) of harmonic minor - but it can be used to lead to major tonics as well as minors.
The rule here is that "one note in the dim7 is a half-step below the root of the following chord".
This is by far the most common use of a dim7 chord, eg, as in the OP's C - C#dim7 - Dm. C#dim7 is the vii chord in the key of D minor, so it "tonicises" the Dm chord. C#dim7 is then a "secondary leading tone chord", written as "vii/ii" (translated as "vii of the ii chord").
As mentioned, you can see this as a rootless A7b9 ("V/ii"), but you don't need to. Both chords function the same way, but they are two distinct chords.
Sometimes the leading tone function is obscured, eg if you see Edim7 going to Dm. "Edim7" is just a misnaming of C#dim7, probably because the bass note is E. That's quite OK, because writing "C#dim7/E" is unnecessarily clumsy! But seeing it as C#dim7 reveals its "viio" function.

3. There is only one remaining possible move for a dim7, which is where "one note of the dim7 is a half-step above the root of the following chord."
AFAIK there is no "official" name for this chord, and "passing diminished" (or maybe "chromatic diminished") is fine.
As m78w said, it usually occurs between two chords a tone apart, typically two min7 chords.
However, m78w's example is wrong, and illustrates type 2 above (the leading tone, vii chord). The type 3 dim7 is always a descending move.
Well-known examples occur in "Night and Day", and a few Jobim tunes.
This usage can also be seen as a vii chord in reverse.
Eg, in the line Em7-D#dim7-Dm7, D#dim7 could be interpreted as vii of Em7. (Think Em to B7/D# if it helps.)
Even so, it is a distinctively different usage of a dim7.
Another common example of the passing diminished is C - Ebdim7 - Dm7 (-G7), which you can hear in a lot of vintage R&B or jump-jive tunes.
You could see that in two ways: Ebdim7 as a "common tone diminished" with C (but not resolving back to C); or you could see C(Maj7) as Em/C, so it looks like the chromatic descent above. You could even see it as a misspelled F#dim7, the vii of G, which just happens to have a Dm7 inserted between!


When it comes to improvisation scales, dim7s always take the WH dim scale. That's easy to remember because it's the dim7 arpeggio, plus another dim7 arp a half-step down - ie the chord itself plus a full complement of chromatic approaches.
Arguably, the leading tone chord could take the relevant harmonic minor scale. So C#dim7 going to Dm could take the D harmonic minor scale (because that's the origin of the chord itself). However, that gives you a couple of notes a half-step above chord tones (D and F), raising the spectre of the "avoid note" . It depends how seriously you take that issue whether you want it to determine your scale choice...

[Nate Miller]

diminished chords can be simple too.

They can be used to substitute for dom7 chords, and in the case of the I-#I-ii, the diminished chord is a substitute for the V of ii. It functions as a secondary dominant, V/ii

Like JonR says, this is a passing diminished chord. You can approach any chord from above or below with a diminish passing chord.

to substitute a dim for a dom7, place the diminished chord on the 3rd, 5th, 7th or b9 of the dom7 chord.

that might get you going while you're working on some of the other stuff. Diminished chords are deep, too, so there's a wealth of material there. I was doing some diminished studies yesterday and learned something new and I've been working with this stuff for 30 years.

[JonR]

diminished chords can be simple too.

They can be used to substitute for dom7 chords, and in the case of the I-#I-ii, the diminished chord is a substitute for the V of ii. It functions as a secondary dominant, V/ii

Well, as I said, it functions as a secondary leading tone chord, vii/ii. No need to consider the V.
IOW, the vii chord is not a substitute. Not unless the original chord in that place was a V, of course.

Like JonR says, this is a passing diminished chord. You can approach any chord from above or below with a diminish passing chord.

Yes, but the difference is enough for it to be useful to give them different names:
From above: passing diminished
From below: leading tone chord, or vii.

to substitute a dim for a dom7, place the diminished chord on the 3rd, 5th, 7th or b9 of the dom7 chord.

Right. That's essentially substituting the vii for the V.
Same idea as using ii instead of IV (or vice versa) when heading for V. (We don't say a IV is a sub for ii.)

Of course, there is a difference with the dim7, in that we use the harmonic minor vii chord in both minor and major keys.
We could easily use a viim7b5 chord as a major key leading tone chord, but in practice it's very rarely done. (Jazz writer William Russo calls the half-dim chord a "leading tone seventh", even though it's normally used as a minor key supertonic.) If it is, then it's certainly regarded as a rootless V9, because viim7b5 is so rare.
But using a viio7 chord to lead to I (or i) is common enough, especially in secondary function, to see it for what it is, and not as a sub for V.
Of course, it can be a sub for V. That doesn't mean it always is, or even is most of the time.

[jordanklemons]

My understanding is the concept is that this is the chord to get a bit excited on, create some tension.

Hmmm... so you would use Fdim7 instead of F7 during the turnaround? To create tension and resolve back to the Bb?

I mean, I would say this...

You can do anything, and get away with anything, and if you want to it's possible to create tension with anything (rhythmic, if nothing else). But for me, I wouldn't use that to create tension in the blues instead of the 5 chord because the Fdim7 sounds less excited and tense than the F7 does to me. The F7 has the 3rd and 7th that are both a half step away from the 3rd and 7th of Bb... which helps create movement, and a feeling of having left home.

F7 -> Bb7
A -> Ab
Eb -> D

If you make the F7 into an Fdim7, then there's no movement. The 3rd and the 7th stay the same.

Fdim7 -> Bb7
Ab -> Ab
D -> D

[gggomez]

Yes I am not hearing it hence my question.

As an experiment where else could you use a diminished line in a blues, may help my understanding.

Apologies I have printed out the above but not read yet am on a spin bike in a gym.

[pingu]

Yeah, they're kind of squirly triple G. They can kind of go anywhere. I'm still trying to wrap my head around them completely.

I used to tend to use them just mostly as a passing chord between two chords a whole step apart. But a few years ago, I realized I was being very disrespectful to (or with) them. I was just relying on the fact that they created tension to make them work. But there's some really subtle issues that arise that I started noticing. And it makes such a world of difference in my ear for how musical they can be.

For instance, in Bye Bye Blackbird, I would sit on the F tonic for a while (maybe with some 2 5s or something for movement), and then in bar 5 (I think) I would use an F#dim7 to resolve me up to the G- where I'd hover for the next few measures. But then it dawned on me that I was using an F#dim7 chord to harmonize a G note. It was tension moving to resolution, and it was short lived... so it sort of worked. But really not harmonious at all. Did not properly accompany the melody. But when I started treated that chord as an Abdim7 chord? Aaaaaahhhh, lovely. It totally embraces that G note in the melody. And it creates a fantastic resolution down a half step to the G-.

They're tricky like that.

you were using F#dim
the Ab dim is equivelent F dim

[pingu]

Cdim7
X3424X
CMaj7
X3545X
F-7
X8686X
Bb7#5
6X677X
Cadd2
X7.10.7.8X
.

looove that last chord JK !