Chord reference · triad
Cdim chord (C diminished)
The Cdim chord contains 3 written tones: C, E♭, G♭. Its interval formula is 1–♭3–♭5.
Cdim chord notes and interval formula
The formula 1–♭3–♭5 means the chord is measured from C using the root, minor third, and diminished fifth. In semitone numbers from the root, the pattern is 0–3–6.
| Degree | Interval | Semitones | Note |
|---|---|---|---|
| 1 | Root | 0 | C |
| ♭3 | Minor Third | 3 | E♭ |
| ♭5 | Diminished Fifth | 6 | G♭ |
How to play Cdim on piano
Start with the notes in root position from low to high: C – E♭ – G♭. Right hand 1–3–5; left hand 5–3–1 is a useful starting point, but black-key combinations and melodic movement may make another fingering more comfortable.
For a cleaner accompaniment, place the root in the left hand and play the remaining tones in the right. With extended chords, keep the third and seventh because they identify the chord quality most clearly.
How to play Cdim on guitar
Try the shape x-3-4-5-4-x in standard tuning, read from low E to high E. The sounding-string details are: E mute; A fret 3: C; D fret 4: G♭; G fret 5: C; B fret 4: E♭; E mute. Keep every note clear and release pressure from strings marked “x.”
This is one voicing, not the only correct shape. The chord remains Cdim whenever the essential pitch classes are present; doubling, omission, and bass-note choice change the voicing rather than the basic chord name.
Cdim inversions and slash chords
Inversions keep the same notes but place a different chord tone in the bass. They are useful for smoother bass lines, compact keyboard movement, and alternative guitar voicings.
| Position | Symbol | Notes low to high | Bass |
|---|---|---|---|
| Root position | Cdim | C – E♭ – G♭ | C |
| 1st inversion | Cdim/Eb | E♭ – G♭ – C | E♭ |
| 2nd inversion | Cdim/Gb | G♭ – C – E♭ | G♭ |
What Cdim sounds like and where it fits
The C diminished chord is tense and unstable. Diminished triads create strong tension. They commonly function as leading-tone or passing chords and often resolve with the root moving up by a semitone. A common voice-leading move resolves the root C upward to D♭.
Cdim compared with similar chords
Small interval changes create different chord names. Use this table to avoid confusing Cdim with nearby structures.
| Chord | Quality | Formula | Notes |
|---|---|---|---|
| Cm | Minor | 1–♭3–5 | C, E♭, G |
| Cm7b5 | Half-Diminished Seventh | 1–♭3–♭5–♭7 | C, E♭, G♭, B♭ |
| Cdim7 | Diminished Seventh | 1–♭3–♭5–♭♭7 | C, E♭, G♭, B♭♭ |
Frequently asked questions
What notes are in the Cdim chord?
The Cdim chord contains C, E♭, G♭. Its interval formula is 1–♭3–♭5.
How do you play Cdim on piano?
Play C, E♭, G♭ together. A practical root-position fingering is right hand 1–3–5; left hand 5–3–1; adjust the fingering to your hand and musical context.
How do you play Cdim on guitar?
One compact standard-tuning shape is x-3-4-5-4-x from the low E string to the high E string. An “x” means mute that string.
What does the symbol Cdim mean?
The root is C. The suffix dim identifies a diminished structure with the formula 1–♭3–♭5.
How many inversions does Cdim have?
A 3-note chord has 3 closed-position arrangements when every chord tone is retained: root position plus 2 inversions. Extended practical voicings may omit notes.