Diminished, Half Diminished, and Augmented Chords

Diminished, Half Diminished, and Augmented Chords

Diminished Chords

The diminished chords are either written as 'dim' or sometimes using a small circle like the symbol for degrees (°).

A diminished chord is made up of these notes:

1st, min 3rd, flat 5th, double flat 7th.

(Double flat 7th is the same note as the major 6th, but it's usually written as double flat 7th - don't ask me why!)

So A diminished would be: A, C, Eb, Gb

As a point of interest, the intervals between successive notes in a diminished chord are all minor thirds.

This means if you start to build a dim chord on a C, you end up with the same notes as for the A dim.

In other words Adim = Cdim = Ebdim = Gbdim = A+C+Eb+Gb

So when you play a diminished chord, if you move it up the neck by 3 frets you still have the same chord!!

There is also a chord called the half-diminished, or diminished 7th. I usually write this one as somthing like E7-5 - just another name for the same chord. It's best if you're aware of the different names used for the same chord.

The difference between this one and a 'normal' diminished is that the 7th of the chord is a flat 7th, not a double flat 7th (hence half-diminished).

So the spelling is 1st, min 3rd, flat 5th, flat 7th.


Augmented Chords

An augmented chord is made up of these notes:

1st, maj 3rd, sharp 5th

So A augmented would be : A C# F

(Intervals between successive notes are all maj 3rds - i.e. 4 semitones.)

You can see augmented chords written as something like 'A aug' or 'A+'.