Chord type
Diminished 7th Chords on Piano
The diminished 7th chord is a symmetrical four-note chord built entirely from minor thirds, dividing the octave into four equal parts. It is the most dramatic and tense chord in tonal music, used for suspense, modulation, and classical cadences.
Pick a key to hear and see it below. Each key opens a full reference entry with a keyboard diagram, audio, inversions, fingerings, and notation.
Featured key
C Diminished 7th Chord
Notes: C - E♭ - G♭ - B♭♭
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Open the full C Diminished 7th Chord reference ›Formula: Root – Minor 3rd – Diminished 5th – Diminished 7th
Intervals: 3 + 3 + 3 semitones (three stacked minor thirds)
Scale degrees: 1–♭3–♭5–°7
Sound: Dramatic, tense, suspenseful, urgent
Symbol: dim7 or °7 (Cdim7, C°7)
Perfect symmetry: Because dim7 divides the octave into four equal parts, there are only three unique diminished 7th chords. Cdim7, E♭dim7, G♭dim7, and Adim7 all contain the same four notes. This makes dim7 the ultimate pivot chord. It can resolve to any of four different keys, making it invaluable for key changes.
Diminished 7th Chord in All 18 Keys
All 18 spellings, ♯ and ♭ keys listed separately.
C Diminished 7th ChordNotes: C – E♭ – G♭ – B♭♭C♯ Diminished 7th ChordNotes: C♯ – E – G – B♭D♭ Diminished 7th ChordNotes: D♭ – F♭ – A♭♭ – C♭♭D Diminished 7th ChordNotes: D – F – A♭ – C♭D♯ Diminished 7th ChordNotes: D♯ – F♯ – A – CE♭ Diminished 7th ChordNotes: E♭ – G♭ – B♭♭ – D♭♭E Diminished 7th ChordNotes: E – G – B♭ – D♭F Diminished 7th ChordNotes: F – A♭ – C♭ – E♭♭F♯ Diminished 7th ChordNotes: F♯ – A – C – E♭G♭ Diminished 7th ChordNotes: G♭ – B♭♭ – D♭♭ – F♭♭G Diminished 7th ChordNotes: G – B♭ – D♭ – F♭G♯ Diminished 7th ChordNotes: G♯ – B – D – FA♭ Diminished 7th ChordNotes: A♭ – C♭ – E♭♭ – G♭♭A Diminished 7th ChordNotes: A – C – E♭ – G♭A♯ Diminished 7th ChordNotes: A♯ – C♯ – E – GB♭ Diminished 7th ChordNotes: B♭ – D♭ – F♭ – A♭♭B Diminished 7th ChordNotes: B – D – F – A♭C♭ Diminished 7th ChordNotes: C♭ – E♭♭ – G♭♭ – A♭