A diminished chord is a type of chord that has a tense, unstable, or unresolved sound, often used to create a feeling of suspense or tension in music. It’s built by stacking minor thirds (three semitones) on top of each other, which makes it unique compared to major and minor chords.

A basic diminished triad consists of the Root, the starting note of the chord. Minor 3^rd, a note three semitones above the root.

Diminished 5^th (or flat 5^th), a note six semitones above the root.

A diminished Triad is made up of the root, minor 3^rd, and diminished 5^th. A diminished seventh (dim7) chord adds a doubly diminished seventh (a minor 3^rd above the 5^th) on top of the triad, creating a four-note chord. It has even more tension than a regular diminished triad.

Diminished chords have a dark, tense, and unresolved sound because of the close intervals (especially the diminished 5^th, which is also called a tritone).

Diminished chords are often used as passing chords to lead to other chords, adding dramatic effect, tension, or dissonance before resolving to a more stable chord. In classical and jazz, they frequently lead back to a tonic or dominant chord.

Below are some diminished chords that can be moved around on the neck.

Portable Diminished with Root on 6^th String

Portable Diminished with Root on 5^th String

Portable Diminished with Root on 4^th String

Portable Full Diminished with Root on 6^th String

Portable Full Diminished with Root on 5^th String

Portable Full Diminished with Root on 4^th String

Portable Half Diminished with Root on 6^th String

This is also a portable half diminished with root on 6^th string with a different fingering. 

Portable Half Diminished with Root on 5^th String

Portable Half Diminished with Root on 4^th String