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Cdim(Diminished Chord)

Built from two stacked minor thirds. Creates maximum tension and instability.

Notes
C – D# – F#
Intervals (semitones)
0 – 3 – 6
Type
Triad

🎹 Cdim on Piano

Press highlighted keys simultaneously to play the Cdim chord.

R
C(Root (R))
2
D#(Minor 3rd (♭3))
3
F#(Tritone (♭5))

🎸 Cdim on Guitar

The Cdim chord uses notes C, D#, F#. Build a voicing by finding these notes on any strings — root on the 6th string is a common starting point for barre chord shapes.

Interval Analysis

DegreeInterval NameSemitonesNote in C
RootRoot (R)0C
3rdMinor 3rd (♭3)3D#
5thTritone (♭5)6F#

About the C Diminished Chord

The Cdim chord (C Diminished) consists of 3 notes: C, D#, F#. Built from two stacked minor thirds. Creates maximum tension and instability.

To build any diminished chord, apply intervals of 0, 3, 6 semitones above the root. Starting from C: the notes land on C, D#, F#.

Playing Cdim on Piano

Press C, D#, F# simultaneously. In root position, C is lowest. First inversion places D# in the bass for a lighter sound; second inversion uses F# as the bass note.

Common Chord Progressions Using Cdim

  • I–IV–V: Cdim – Fdim – Gdim (blues and rock)
  • I–V–vi–IV: Cdim – G – Am – F (pop staple)
  • I–vi–IV–V: Cdim – Am – F – G (50s progression)

The Cdim Chord in Context

As a diminished chord, Cdim is the tonic (I) in the key of C major. It also appears as the IV chord in G major, and as the V chord in F major — making it one of the most important chords across all of Western music.

Other C Chords

C
Major
Cm
Minor
C7
Dominant 7th
Cmaj7
Major 7th
Cm7
Minor 7th
Caug
Augmented

Diminished Chord in All 12 Keys

CdimC#dimDdimD#dimEdimFdimF#dimGdimG#dimAdimA#dimBdim
🎹 Virtual Piano
Play Cdim on piano
🎸 Virtual Guitar
See on the fretboard
🎵 C Scale
Notes that fit Cdim
🎶 Songs
Find songs using Cdim

FAQ

Cdim Chord — Frequently Asked Questions

What notes are in the Cdim chord?
The C Diminished chord contains: C, D#, F#. These notes are derived by applying the diminished interval formula (0–3–6 semitones) to the root note C.
What is the Cdim chord used for?
Built from two stacked minor thirds. Creates maximum tension and instability. The Cdim chord is used across pop, rock, jazz, and classical music. As the I chord in the key of C major, it functions as the most stable resting point in progressions.
How do you play Cdim on piano?
On piano, play C, D#, F# simultaneously. In root position, C is the lowest note. Inversions move the bass note up — first inversion has D# lowest, second inversion has F# lowest.
How many notes are in a diminished chord?
A diminished chord has 3 notes: C, D#, F# (in C). It is a triad — the most fundamental chord type.
What is the difference between C major and C minor?
The C major chord (C–E–G) uses a major third (4 semitones), giving it a bright, happy sound. The C minor chord (C–D#–G) uses a minor third (3 semitones), giving it a darker, emotional sound.
What key does Cdim belong to?
Cdim naturally serves as the I chord in the key of C major. It also appears as IV in the key of G major, and as V in the key of F major.
Can I play Cdim on ukulele?
Yes. The ukulele uses GCEA tuning with 4 strings. The Cdim chord notes (C, D#, F#) can be fretted on a ukulele, though the shapes differ from guitar due to the 4-string layout and shorter scale.
What chords go well with Cdim?
In the key of C major, Cdim pairs naturally with F major (IV), G major (V), and Am (vi). The classic I–IV–V (Cdim–F–G) is the foundation of blues, country, and rock.
What is a chord inversion of Cdim?
An inversion places a non-root note in the bass. Cdim root position: C in bass. First inversion: D# in bass. Second inversion: F# in bass. Inversions create smoother bass line movement without changing the harmony.
How do I memorize the notes in a diminished chord?
Remember the formula: 0–3–6 semitones from root. For Cdim: start on C, add 3 semitones, then 6 semitones. Practicing this across all 12 roots builds instant recognition of any diminished chord.