Diminished Triads on Guitar
In previous lessons we’ve explored both major triads and minor triads, which are two of the most commonly used triads. In this lesson we round out the triads of the major scale with a look at diminished triads. These triads naturally occur on the seventh degree of the major scale. They’re a bit dark, gloomy, and unstable, which make them good to use as passing chords.
Diminished Triads
Diminished triads consist of a root, minor 3rd, and diminished 5th interval.

Triads are built using stacked thirds, which means each of these intervals is a 3rd apart. The diminished triad consists of two minor 3rds.
- Minor 3rd = 3 semitones (3 frets)
Quality | Stacked 3rd Intervals | Semitones | 5th Quality |
---|---|---|---|
Minor | Minor 3rd + Minor 3rd | 6 | Diminished |
Diminished Triads on the Fretboard
Similar to major and minor triads, diminished triads can be mapped to the fretboard using grouping of three strings. Again, we’ll have four groupings of three using strings 1-2-3, 2-3-4, 3-4-5, 4-5-6.
Diminished Triad Shapes on Strings 1-2-3
On strings 1-2-3, we get the following note arrangements:
- Shape 1 (1st inversion): 3rd on string 3, 5th on string 2, root on string 1
- Shape 2 (2nd inversion): 5th on string 3, root on string 2, 3rd on string 1
- Shape 3 (root position): root on string 3, 3rd on string 2, 5th on string 1

The following diagram shows all three shapes up the fretboard. After shape 3, the shapes will repeat again starting with shape 1.


Diminished Triad Shapes on Strings 2-3-4
The note arrangements for strings 2, 3, and 4 are as follows:
- Shape 1 (root position): root on string 4, 3rd on string 3, 5th on string 2
- Shape 2 (1st inversion): 3rd on string 4, 5th on string 3, root on string 2
- Shape 3 (2nd inversion): 5th on string 4, root on string 3, 3rd on string 2

Diminished triads up the fretboard for strings 2, 3, and 4 are shown in the diagram below.


Diminished Triad Shapes on Strings 3-4-5
The note arrangements for strings 3, 4, and 5 are as follows:
- Shape 1 (2nd inversion): 5th on string 5, root on string 4, 3rd on string 3
- Shape 2 (root position): root on string 5, 3rd on string 4, 5th on string 2
- Shape 3 (1st inversion): 3rd on string 5, 5th on string 4, root on string 3

Below are the shapes up the fretboard.


Minor Triad Shapes on Strings 4-5-6
For strings 4, 5, and 6, diminished triads have the following note arrangements:
- Shape 1 (1st inversion): 3rd on string 6, 5th on string 5, root on string 4
- Shape 2 (2nd inversion): 5th on string 6, root on string 5, 3rd on string 4
- Shape 3 (root position): root on string 6, 3rd on string 5, 5th on string 4

Diminished triads up the fretboard on strings 4, 5, and 6 are shown below.


Wrap up
In this lesson we looked at diminished triads, which occur on the seventh degree of the major scale. These triads contain a root, minor 3rd and diminished 5th interval. Diminished triads are dissonant, which makes them ideal for use as passing chords.
Spend time learning them on each of the string combos up and down the neck. To make it more fun, substitute these triad shapes for full diminished chords you find in chord progressions or include them in your own chord progressions.
Get notified of new lessons!
Get the free Book of Scales ebook when you sign up for lesson updates.

Cheat Sheet: Diminished Triads
Download the cheat sheet for this lesson: