Cdim7 Chord (Diminished 7th)

Fully diminished 7th stacks minor 3rds all the way up — root, flat 3rd, flat 5th, double-flat 7th — a perfectly symmetric chord. The notes of Cdim7 are C, D#, F#, A.

Maximum tension with nowhere obvious to land: horror-film harmony, ragtime passing chords, and the chord jazz players use to slide chromatically between two others.

Cdim7 voicings on guitar

Every playable, root-in-the-bass grip standard tuning offers, computed from the chord’s own formula — not a fixed shape library.

Because every interval is identical, the same shape moved up three frets is still a dim7 — try sliding it and hear how little actually changes.

Formula and intervals

R - b3 - b5 - 6 — 4 notes.

Scales that fit Cdim7

Every scale below contains all of this chord’s notes — safe territory to improvise in over it.

Diminished (HW), Diminished (WH)

Other sevenths on C

• Cmaj7 (Major 7th)
• Cm7 (Minor 7th)
• C7 (Dominant 7th)
• Cm7b5 (Half-Dim 7th)
• CmM7 (Minor-Major 7th)
• Caug7 (Augmented 7th)