A Unique Animal

Diminished 7th chords are unique animals. They have some unusual qualities that make them interesting and useable. For example, they are the only type of chord that is simply a stack of minor 3rds. If you count from one chord note to the next, you will find that they are all equidistant.

This is what they look like on paper:

A Dimished Chord

is a chord built in minor 3rds from the root up, and appears in leadsheets as any of the following chord symbols:

A diminished chord occurs most frequently in jazz and popular music as a four-note chord, as shown above, regardless of whether the symbol says Co or C07. The 7th of the chord is a diminished 7th, but is sometimes spelled as a major 6th.

There are really only 3 diminished 7th Chords:


Any note in this diminished 7th chord can function as the root -- therefore this chord could be named

Cdim7,

Ebdim7 or D#dim7

F#dim7 or Gbdim7

Adim7, or Bbbdim7.

 



Any note in this diminished 7th chord can function as the root -- therefore this chord could be named

C#dim7 or Dbdim7

Edim7

Gdim7

A#dim7 or Bbdim7.

 



Any note in this diminished 7th chord can function as the root -- therefore this chord could be named

Ddim7

Fdim7

G#dim7 or Abdim7

Bdim7 or Cbdim7.

 

 



When we get into chord progressions, we will see that diminished 7th chords can be used as "modulation agents," "transposition agents," and "transition agents." So learn them well in ALL inversions.

This page updated on October 26, 2013.