Slightly OT harmony question

Living in the Ozark Plateau and rubbing shoulders every day with instinctive / intuitive musicians who mostly don’t read music but do everything by ear, I find myself, as a classically trained person from the age of five who didn’t even try anything non-classical till I was about 50, straining to explain what I mean sometimes in terms they will understand. (For example, what I call a V of V chord, they call a Major-2 chord, which drives me slightly nuts, since there is really no such thing, but oh well.)

My question is, how do I Create a chord symbol that means Fully-diminished 7th? I know how to do it for half-diminished, but am stumped when it comes to fully.

Let’s say I’m arranging a piece in D, and I come to a sequence that goes: D / G / G#-fully-diminished / 2nd-inversion-D / B minor, etc. I’ve learned how they expect to see a 2nd inversion chord, namely, in this case, D/A. But I don’t have a clue about the fully-diminished G# chord, and sadly I don’t even know how to ask the question without sounding retarded. (I don’t mind sounding retarded HERE, obviously!)

Any suggestions?


if I’m understanding your question right.
don’t put a slash through the circle. (that is half-dim)

the circle is usually superscripted.

I really don’t understand the question. G#dim? Dm6(omit5)/G#? Bdim/G#?

Pianoleo, yes it could certainly be written Bdim/G#. I’ll try that on people and see how they react. I’ll also try it shr23’s way and see which way causes less consternation.



Pretty straightforward. C-Eb-Gb-A would be written as Co7, with the “o” superscript, as shr23 said. That’s standard convention.

Even G#o would be fine - the double flatted seventh will be played. If I didn’t want a seventh I would take pains to say that with ‘no 7’ or ‘triad’.

It is standard, but the “classical” guys might get irritated that Co7 ought to be C-Eb-Gb-Bbb, and C-Eb-Gb-A is Ao7/C.

If you believe everybody always plays and sings in equal temperament they sound the same, but if you are bothered about showing harmonic function they are still different animals.

Quite right, I was speaking enharmonically.

Probably my favourite collection of Dim 7 chords - Bach sticking two fingers up at the musical establishment he worked for, in BWV715.

I wonder how many marks you would get in a modern theory exam if you harmonized a chorale that way? :slight_smile:

Wow - thank you Rob, I did not know this piece. Holy cow!

As regards the conventions of diminished chords in his day, “sacred cow” might be more apropos. :laughing:

I wasn’t familiar with this one either. Wow.

“G# dim.” is standard in popular music for a complete G# diminished seventh chord. See Wikipedia article mentioned above.

John, If I came across a chord labeled G# dim in a piece, I would interpret that as a triad, not a 7th chord!?! The problem I’m encountering is that once you specify it as a 7th, then how do you differentiate between half and fully diminished for the average musician who doesn’t know theory.

To all: (and thank you)

I tested a couple of the above suggestions on some of my favorite ‘guinea pigs’ today, and the winner was Pianoleo’s idea to use Bdim / G#. Caused less confusion and questioning than any other combination. Most people around here don’t know what the little circle means, for example.


The circle for dim and the slashed circle for half-dim are the most used. Outside of classical music ‘B dim/G#’ would lead to head-scratching as to why it’s not G#dim. Even in the classical world, no-one plays a G#dim arpeggio without the (double-flatted) seventh.