C Diminished Chord

The notes are C (root), E flat (minor third) and G flat (diminished fifth). Their formula is 1-flat 3-flat 5. Count three semitones from C to E flat, then three more to G flat. G flat is a diminished fifth above C, six semitones from the root.

The diminished fifth is a tritone above the root. Playing only C and G flat isolates the interval; adding E flat shows how it sits inside the full chord. You may see the triad written Cdim or C°.

Move the lowest note up an octave while keeping the same pitch classes:

A change of position does not add a new note. Play each inversion broken and listen for the tritone even when its two notes no longer sit at the outside of your hand shape. Chord Inversions explains how the bass changes the reading.

Keep C and E flat; raise G flat by one semitone to the perfect fifth and you have C minor. Reverse the move to hear the diminished chord again. Compare with C Minor Chord using the same root and volume. A one-key change makes the diminished fifth much easier to identify than an abstract label like “unstable.”

No. Cdim is the three-note triad above. Cdim7 adds a diminished seventh as a fourth note. Some charts use “dim” loosely, so listen to or check the actual notes before assuming the seventh is present. Diminished Chord separates the two structures.

Play C minor, lower only its fifth, then raise that fifth again. Next, play the diminished triad with E flat in the bass. If you still recognize the six-semitone root-to-fifth distance after the inversion, you are hearing the structure rather than memorizing one keyboard shape.