• Lesson Information

Lesson 26.5 – Cdim7 Chord Formations

Diminished chords are similar to half-diminished chords with one exception. Instead of a minor (flat) 7th, a diminished chord has a double flat (bb)7th. So, diminished chords are made with a root, minor (flat) 3rd, diminished (flat) 5th and double flat 7th, which is the equivalent of a whole step, or two frets. Common notations for diminished 7th chords are o7 and dim? {e.g. Co7, Cdim7).

Diminished 7th Chords

Co7 Chord (Root on 6th)

Co7 Chord (Root on 5th)

Co7 Chord (Root on 4th)