C Diminished chord — Open G

About C Diminished in Open G

The C Diminished chord contains the notes C, D#, F#. 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.