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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.

Diminished triad intervals in the chromatic scale

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)
QualityStacked 3rd IntervalsSemitones5th Quality
MinorMinor 3rd + Minor 3rd6Diminished

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
Guitar diagram for diminished triads on strings 1, 2, and 3

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

Diminished triads up the guitar fretboard on strings 1, 2, and 3
Guitar tab for diminished triads on strings 1, 2, and 3

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
Guitar diagram for diminished triads on strings 2, 3, and 4

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

Diminished triads up the guitar fretboard on strings 2, 3, and 4
Guitar tab for diminished triads on strings 2,3 and 4

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
Guitar diagram for diminished triads on strings 3, 4 and 5

Below are the shapes up the fretboard.

Diminished triads up the guitar fretboard on strings 3, 4, and 5
Guitar tab for diminished triads on strings 3, 4, and 5

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
Guitar diagram for diminished triads on strings 4, 5, and 5

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

Diminished triads up the guitar fretboard on strings 4, 5, and 6
Guitar tab for diminished triads on strings 4, 5, and 6

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.

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