diminished seventh flat ninth chord?

[terriandralph]

I know that the diminished seventh chord can be thought of as an incomplete ninth with the root omitted. For example, the V chord in Cm (G7b9) with the root omitted, would be B, D, F, and Ab, and the appearance of the Ab in the chord being the result of adding yet another third to the V7 chord, with the Ab coming from the Cm scale.

However, to follow up on the example I gave earlier, I am having trouble finding a chord built with the following pitches: B, D, F, Ab, C (a diminished seventh flat ninth chord)? I am not well versed in jazz theory, but I was thinking that perhaps the reason I am having trouble finding this chord is because adding C to the chord produces essentially an incomplete eleventh flat ninth chord that is missing the root, and the eleventh chord usually does not appear with the major third because it conflicts with the eleventh (which if I understand correctly is why the eleventh is sharped if the major third does appear in an eleventh chord).

At any rate, is this a chord that any of you guys are familiar with?

[fmr]

This chord belongs to the tonality of C minor. Adding a C to the chord, you are basically anticipating the resolution, or creating an overtonic chord. This is what I can tell based on the theory I studied (which was music theory).

[jancivil]

it isn't going to be much found for the reason you already noticed.

It works pretty much as a dominant 7 natural eleventh, which isn't stylistically apt, which is true because of the quality of it, the sharp 11 is the more natural resonance given the rest of the harmony. 11th partial from the root, 9th partial per the 3rd... while a minor ninth from the third is... awkward; 'you doin' too much'.

that doesn't mean a line chancing on the C over that harmony is a bad note, however. you wouldn't emphasize it unless you're trying to be yoogly.

natural 11ths are going to tend to accord with minor triads...

[jdlvoltron]

To me, I would think the C would sound like a non chord tone anticipating C minor

[NKF]

it is part of the octotonic scale that can outline that chord so nothing out of the ordinary. Hard to explain something out of context. It is also the danger of looking at vertical chunks too literally when using western theory conventions.

[jdlvoltron]

It is also the danger of looking at vertical chunks too literally when using western theory conventions.

Words of wisdom

[jancivil]

it is part of the octotonic scale that can outline that chord so nothing out of the ordinary. Hard to explain something out of context. It is also the danger of looking at vertical chunks too literally when using western theory conventions.

the OP found no context. There is a reason for that and it is strictly about the quality of it vertically speaking, literally speaking. in jazz practice, chords are built vertically, literally and this one isn't usual. you could end up with it phenomenally, but you won't see that one in a chart really.

[fmr]

it is part of the octotonic scale that can outline that chord so nothing out of the ordinary. Hard to explain something out of context. It is also the danger of looking at vertical chunks too literally when using western theory conventions.

the OP found no context. There is a reason for that and it is strictly about the quality of it vertically speaking, literally speaking. in jazz practice, chords are built vertically, literally and this one isn't usual. you could end up with it phenomenally, but you won't see that one in a chart really.

Because it isn't really a chord? As I said, and someone else pointed to, the diminished seventh is straightforward (belongs to C minor). The C is just an added note not belonging to the chord, anticipating the resolution.
Of course, being the diminished seventh a symmetrical chord, you can resolve it to a lot of tonalities, depending on the names you "call" the notes.

[jancivil]

The C is just an added note not belonging to the chord, anticipating the resolution.

Not necessarily; it could be what you said. The OP said: "dim7 b9".

being a symmetrical chord, you can resolve it to a lot of tonalities, depending on the names you "call" the notes.

True enough, per your assumption it's a diminished seventh chord and not more. But. With that C, that symmetry is obviated.

The OP calls it a chord, a vertical structure, qua chords, in jazz. There is no reason it can't be a chord.
But, NB: The Original Post indicated no findings of this one, as given, in the literature.

Really, terriandralph understand what's happening perfectly well with their reasoning. The practice is to avoid a natural eleventh on a dominant 7th, which this implies. You aren't following that reasoning, which I think is sound reasoning. >EDITED for a not real clear statement.

as I said, hitting a C in the line as a horn player is not a bad note, it 'anticipates [the tonic]'. Anticipation in lines is done all the time. But, I don't think it'll be real easy to find in chord charts.

[Arrested Developer]

I know that the diminished seventh chord can be thought of as an incomplete ninth with the root omitted. For example, the V chord in Cm (G7b9) with the root omitted, would be B, D, F, and Ab, and the appearance of the Ab in the chord being the result of adding yet another third to the V7 chord, with the Ab coming from the Cm scale.

In theory, the diminished seventh chord is mostly seen - as you write - as an uncomplety ninth with the root omitted.
What is mostly forgotten, is the fact that in the time of its origin - in the baroque era - this chord also could have a second meaning, which is mostly forgotten since modern theory tries two watch only the assembly of thirds.:

In its other meaning, this chord was understood - if we stay in c-minor - as a substitue for the half-diminished chord of the II-degree. So, instead of D-F-Ab-C they mostly took B instead of C, so in this case B could be seen as a "suspended note to C; while D is the fundamental tone of the chord.

Sounds strange?
In fact, this is very seldom mentioned in theory.
I found this explanation e. g. in a book of Kirnberger (a direct pupil of J. S. Bach), where he does an analyse of a preludium of Bach (a-Moll, of the WTC II).

Also, it explains lot of chord progressions in Bach's music:
so, if he writes a chord progression: D-f-ab-h which goes to G7, it's in fact a falling fifth in the fundamentals
(an not the senseless progression V-V.

Now, with this answer, you have an explanation why the chord b-d-f-ab-c is found seldom: it would combine the "meant" note c with its substitute.
Nevertheless, this chord can be found - in Bachs music.
In fact, if you carefully analyse the immanent voicing in his Prelude I (WTC 1, BWV 846) you find the chord ab-f-b-c-d in bar 23. One could think that C in this situation is only a passing note, but it isn't: in the next bar, b progresses to g and c progresses to b (also this two bars mean a II-V progression in C-major, while here ab of course is a chromatic alteration.



Anyhow, if you like this chord b-d-f-ab-c, you should use it.

[Arrested Developer]

p.s. of course, in the case where b-d-f-ab is an uncomplete G9b, C has the function of an anticipated resolution of B, which is used simultaneously whith B.

What also can be interesting, is to use an additional Db instead of C. This would be an additional - but diminished -
fifth to G. It would give you an even stronger but yet cool sounding tension, since you have an additional leading note to C.
so this chord would be: (G-) B-D-F-Ab-Db, which solves into C-Eb-G-C-C

Or - an this is also wonderful (depending of the harmonic context) you understand it as C# and progress to cmin-9.
-> (G-)-B-D-F-Ab-C# which solves into either C-Eb-G-C-D or C-Eb-G-Bb-D (c-min7/9)

As long as you keep track of the melodic propensity of the notes, such latent bitonality sounds great!

[jancivil]

quoted rather than edited

[datroof]

I would see this as a diminished arpeggio, with the C informing which diminished scale to use, which in turn gives you the other available notes/extensions. Also, C harmonic minor contains these notes, which can be used to suggest a bunch of other sounds.

[jancivil]

Sure, that all makes sense. C as the tonic over the other thing doesn't have to be a chord tone, as fmr said but I was argumentative.

As a chord it's not one o' the usual suspects in regular jazz ideation. It could be hip, though.

[datroof]

These "what label do I put on [random group of notes]" questions can lead to interesting discussion. I run into this a lot, trying to figure out what's the simplest - or easiest to read - label for a quirky group of notes. It's a good mental exercise if nothing else.