A Diminished chord — Open G

About A Diminished in Open G

The A Diminished chord contains the notes A, C, D#. In Open G tuning (strings: D–G–D–G–B–D), the chord shapes differ from standard tuning because the open string pitches change. Open G tuning lets you play a G major chord across all open strings — widely used in blues and slide guitar. Diagrams above show all playable shapes in this tuning.