Diminished chords are represented with a small circle to the right of the chord name and are made up of the 1st b3rd b5th & bb7th of the Tonic scale, or put simply stacked minor 3rds. Note in the diagrams below how every note in the Diminished chord can be the Tonic. By moving the chord 3 frets up or down the neck you will see that the notes in the chord are the same but just in a different order. This is very handy as you are never far away from any diminished chord shape. To find out more about Diminished chord substitutions refer to the Diminished Scales Page .