Baffled by Diminished Chords

I am at my memory's limit for learning new chord shapes.

Because one key's diminished sounds very similar to another's dominant 7, I would likely try to use a 7 as a substitute wherever it "works," as I already know those shapes.

Example: When the music wants a Fdim, what x7 do I try instead? It is C#7?

How can I choose a substitute using the Circle of 5ths?

-Wiggy

Wiggy said:

I am at my memory's limit for learning new chord shapes.

Because one key's diminished sounds very similar to another's dominant 7, I would likely try to use a 7 as a substitute wherever it "works," as I already know those shapes.

Example: When the music wants a Fdim, what x7 do I try instead? It is C#7?

How can I choose a substitute using the Circle of 5ths?

-Wiggy

Click to expand...

Absolutely correct that the dim7 is generally a "dominant" quality. There's a trick to the dim7 in that it's constructed symmetrically of tritones, each of which has two possible resolutions, formally depending on the enharmonic spelling, but in the pop music most of us play, it's seldom that rigorous.

F dim7 is f-ab-b-d. Okay so . . . look at the tritones (Aug 4 or Dim 5, depending on how it's spelled)

f-b is the same tritone as G7. BUT if you spell it as Cb-F, it becomes the tritone of Db7.
In the same way, G#-D is the tritone of E7, but of you spell it D-Ab it's the tritone from Bb7.

Sooooo, you can use Fdim7 for G7, Db7, E7, and Bb7. You can also use it for the corresponding b9 chords, especially if you have a bassist picking up the missing root tone.

Glen Rose (Jazzy Ukulele) calls them "Chameleon Chords" Great fun!

Ah-hah...

My example (Bye Bye Blues) progression is: F Fdim GM7 C7 F (that should be Gm7)

As you suggested, I tried substituting G7, C#7, E7 and Bb7 for the Fdim as they all "worked," but in very different ways. The Chamelon revealed itself

In this case, the C#7 best fit the melody.

Very cool; thanks!

<edit> Responding to Ubulele: "Because for dim7 you only have to learn one shape, which applies to all four strings (i.e., the root could be any of the notes in the shape)—dim7s are dead easy to learn. When you see a chord like Adim in a lead sheet, odds are very high that what the notator actually means is dim7, not a diminished triad."

When I get comfortable with this (dim), I'll look into dim7s.

You are quite correct about the GM7; it is in fact shown as: F Fdim Gm7 C7 F.

This is from the Daily Ukulele To Go, pg 41.

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What I learned about the "Chameleon Chords" and how to find them using the Circle of 5ths:

Fdim7 CCW 4 Db7/Bb7 - Bb7 is Db's rel minor's M7 (Db7 is the most similar to Fdim7)

CW 2 G7/E7 - E7 is G's rel minor's M7

Here's another example; working around A major, instead of F major:

Adim7 CCW 4 F7/D7 - D7 is F's rel minor's M7 (F7 is the most similar to Adim7)

CW 2 B7/G#7 - G#7 is B's rel minor's M7

Thanks to All! (The same for ripock's comment about using dim7.)

It will take years to get comfortable with dims with all those muted internal strings. Save yourself the headache and run to the sweet solace of the dim7. I have never ever found a dim7 not to work in the musical context of a dim. And it is so easy; only one shape and all you need to do is make sure one of your fingers is fretting the note you want and you are set.