What are Augmented and Diminished Chords?

What exactly are augmented and diminished chords? What is the difference between them and major and minor chords?

The short answer:

• A major chord has a Perfect 1st, Major 3rd, and Perfect 5th

• A minor chord has a Perfect 1st, Minor 3rd, and Perfect 5th

• An augmented chord has a Perfect 1st, Major 3rd, and Augmented 5th

• A diminished chord has a Perfect 1st, Minor 3rd, and Diminished 5th

Put another way, an augmented chord is simply a major chord with the 5th sharpened (up 1 semitone). A diminished chord is a minor chord with the 5th flattened (down a semitone).

Don’t worry, we still have a slightly longer and more informative answer:

Like major and minor chords, these chords are what are called triads. A triad is a set of 3 notes that can be stacked in thirds. In other words:

• The first note to the second note is a type of 3rd
• The second note to the third note is a type of 3rd

Another way to look at a triad is this:

• The distance between the first and second note is a type of 3rd
• The distance between the first and third note is a type of 5th

So a triad is basically a 1st, 3rd and 5th.

How we get different types of chords are by changing the quality of the interval, as the numbers will stay the same.

So, triads basically look like this:

For both major and minor chords (or triads), we have a 1st and a perfect 5th. It is simply the note in the middle, the 3rd, that is different.

For diminished and augmented chords, we take the minor and major chords (respectively) and change the quality of the 5th.

In both cases, we are doubling down for what the chord is doing. In a major chord, we have a Major 3rd (the higher between major and minor), so for an augmented chord we ALSO raise the 5th from perfect to augmented.

A diminished chord is doubling down on what a minor chord is doing, so we keep the minor’s Perfect 1st and Minor 3rd, but then also lower the 5th by a semitone from a Perfect 5th to a diminished 5th.

A diminished chord is a minor chord with a lowered (diminished) 5th.

An augmented chord is a major chord with a raised (augmented) 5th.

If you recall from our post on intervals, a major 3rd is 4 semitones from the root note. A minor 3rd is 3 semitones from the root.

Perfect 5ths are 7 semitones away from the root, so Diminished 5ths are 6 semitones away and Augmented 5ths are 8 semitones away.

So let’s figure out a C Diminished chord.

Since it’s diminished, we know the 3rd is a minor 3rd, or 3 semitones, from the root.

C -> Db (1)  -> D (2) -> Eb (3)

So the second note of a C diminished triad is an Eb.

For the 5th, it is a diminished 5th, so:

C -> Db (1)  -> D (2) -> Eb (3) -> E (4) -> F (5) -> Gb (6)

So a C diminished triad is a C, Eb and Gb. Put another way, a C minor triad with a flattened 5th.

Now, let’s do an augmented triad.

We start with a major 3rd, which is 4 semitones from the root.

C -> Db (1)  -> D (2) -> Eb (3) -> E (4)

Next, we raised the 5th to an augmented 5th

C -> Db (1)  -> D (2) -> Eb (3) -> E (4) -> F (5) -> Gb (6) -> G (7) -> Ab (8)

Now, it is an Ab, but we would call it by its other name, G#, because we know our triad is a 1st, 3rd, and 5th. Ab would be seen as a 6th, (C -> A), but a G# would be seen as it is intended here – a sharpened 5th.