C Diminished Seventh Chord

Chord Tones: C Diminished Seventh Chord

Symbol: dim7, °7 — Formula: 1-♭3-♭5-𝄫7

DegreeNoteFrequency (A=440, Equal)
1 C 261.626 Hz
♭3 D# 311.127 Hz
♭5 F# 369.994 Hz
𝄫7 A 440.000 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolCdim7
All Common Symbolsdim7, °7
Interval Formula1-♭3-♭5-𝄫7
Harmonic Categorytense

Roman numeral (e.g. I, IV, V) and Nashville Number notation are key-dependent. See Keys pages for chord function within specific keys.

Inversions

InversionNotes (low to high)Bass NoteSlash Notation
Root Position C D# F# A C C Diminished Seventh Chord
First Inversion D# F# A C D# C Diminished Seventh Chord/D#
Second Inversion F# A C D# F# C Diminished Seventh Chord/F#
Third Inversion A C D# F# A C Diminished Seventh Chord/A

Harmonic Function

The C diminished seventh chord commonly functions as the tonic (I) in C major/minor. Its harmonic role varies by key — in major keys it provides extended harmonic tension.

The diminished seventh chord consists of four equally-spaced minor thirds, creating a symmetrical, highly dissonant chord. It is used as a dramatic pivot chord and in chromatic passing harmony.

Common Progressions

The C Diminished Seventh Chord frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

Songs Featuring the Diminished Seventh Chord

Well-known songs where the C Diminished Seventh Chord — or this chord type — plays a prominent role:

Tuning Frequencies Across Temperaments

Frequencies shown at A=440 Hz. View full temperament data for any note.

NoteEqual Temp.PythagoreanJust Intonation
C 261.626 Hz 260.740 Hz 261.626 Hz
D# 311.127 Hz 309.026 Hz 313.951 Hz
F# 369.994 Hz 371.251 Hz 367.911 Hz
A 440.000 Hz 440.000 Hz 436.043 Hz

Scales Containing the C Diminished Seventh Chord

These scales include the C Diminished Seventh Chord as a diatonic or characteristic chord: