Diminished chords

A diminished chord is a 3-note chord — the root plus a minor third and a diminished fifth above it. Both the third and the fifth are lowered a semitone, stacking two minor thirds.

It sounds tense and edgy, most often slipped in as a passing chord between stronger harmonies. Below are the diminished chords for all twelve keys, from C to B — pick any chart for its full set of voicings, the piano shape and how it's built.