Diminished – Augmented

On this page we will cover the theory behind Diminished chords and Augmented chords. Although not the same type of chords Diminished and Augmented have a one thing in common and that is that the fifth is changed. A flat five chord (fifth is moved down one fret) is diminished and a sharp five (fifth moved up one fret is an augmented chord.


Lets start by looking at Diminished chords. When I think about the Flat Five sound or diminished sound the first thing that comes to mind is ghostly music or scary sounds. You can be sure that any soundtrack from a horror film is going to be loaded with diminished chords.

Lets look at three variations or positions for the Diminished Triad Chord. In this case it’s C-Diminished. If we move the patterns in the video up two frets for example the chords will become D-Diminished chords.

Now lets extend the chord to a diminished 7th. This means we add the fourth note to the mix.  Instead of the repeated root note we now have a double-flat 7th or a perfect 6th depending on how you look at it. Don’t worry to much about the distinction.

The formula: 1 –  ♭3 – ♭5 – 6(7)



Conversely the ‘Augmented’ raises the fifth up one step or fret. A chord with a sharp fifth is an augmented chord. Like before we will start by looking at the augmented triad.

  • Augmented Triad has three notes. Triad = 3
  • Augmented Triad has the formula: 1 – 3 – #5
  • Augmented Triad is a Major chord because the 3rd remains unchanged from the original major scale.

Like before lets look at three variations of the same chord. Starting with the Root (C-note) on the Low E string.

If we extend the chord by adding the 7th (the fourth note) we have: C Augmented Major 7th .

  • Augmented Major 7th has 4 notes.
  • The Formula looks like this: 1 – 3 – #5 – 7
  • This is still a Major Chord since the 3rd remains unchanged from the Major Scale