C Diminished Triad

Chord Tones: C Diminished Triad

Symbol: dim, ° — Formula: 1-♭3-♭5

Chord Notation

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

Inversions

Harmonic Function

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

The diminished triad features a flat third and flat fifth, creating a tense, unstable sound. It occurs naturally on the seventh degree of the major scale and resolves strongly to the tonic. The C Diminished Triad specifically contains 3 notes: C, D♯, F♯ (formula: 1-♭3-♭5). On piano, C-rooted chords sit entirely on white keys in their basic triad form, making them the first chords most students learn. Pop, folk, and singer-songwriter music heavily use C-rooted chords because open-position guitar voicings and piano shapes are immediately accessible.

Common Progressions

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

• viidim-I
• iidim-V

Songs Featuring the Diminished Triad

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

• Whole Lotta Love – Led Zeppelin (bridge)
• Killing Me Softly – Roberta Flack
• Black Magic Woman – Santana

Tuning Frequencies Across Temperaments

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

Scales Containing the C Diminished Triad

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