C sharp Diminished Chord (C♯dim)

1Composition: what it contains

C♯ – E – G

Symbol

C♯dim

Also written

C♯dim, C♯°, C♯m♭5, C♯mi(♭5)

Formula

1 ♭3 ♭5

Same sound as

D♭dim

2Appearance: diagrams and sound

On the guitar

On the ukulele

On the piano

On the staff

On bass and as an arpeggio

3Indications: what it is used for

The vii° chord of a major key and the ii° chord of a minor key are diminished triads. It works as a leading-tone chord resolving to the tonic (vii°–I), as a passing chord between two diatonic chords (for example between I and ii, or IV and V), and as an incomplete dominant seventh: the vii° triad contains the 3, 5 and 7 of V7. Classical, jazz, gospel and film music use it for tension and chromatic movement in the bass.

4Dosage: how to practise it

On piano, play the triad in all inversions at 60 BPM, then practise vii°6–I resolutions with smooth voice leading (the diminished fifth contracting to a third). On guitar, learn the compact three-string shapes on the top strings and the shape rooted on the fifth string. Practise the passing progression I–♯I°–ii–V slowly, then at 80–100 BPM. Arpeggiate 1-♭3-♭5 on bass. Five minutes a day is enough once the shapes are known.

5Warnings and common mistakes

Do not confuse the triad (dim) with the diminished seventh chord (dim7 or °7) or the half-diminished seventh (m7♭5 or ø7): many charts write 'dim' when they mean the four-note dim7, so check the style. The diminished fifth is not a perfect fifth; on guitar, power-chord habits make players play the wrong fifth. In root position the triad can sound harsh; first inversion is the most common classical voicing.

6Interactions with chords, scales and keys

Inversions

• Inversion 1 · C♯dim/E · E – G – C♯ Play
• Inversion 2 · C♯dim/G · G – C♯ – E Play

Scales to play over C♯dim

• C sharp Locrian Mode
• C sharp Blues Scale
• C sharp Half-Whole Diminished Scale
• C sharp Whole-Half Diminished Scale
• C sharp Hungarian Minor Scale
• C sharp Altered Scale

Where it appears (keys and Roman numerals)

• vii° – Key of D Major
• ii° – Key of B Minor

7Other presentations available

The same chord from every note

Cdim Ddim E♭dim Edim Fdim F♯dim Gdim A♭dim Adim B♭dim Bdim

Other chords on C♯

C♯ C♯m C♯aug C♯sus2 C♯sus4 C♯5 C♯6 C♯m6 C♯7 C♯maj7 C♯m7 C♯m7♭5 C♯dim7 C♯m(maj7) C♯7sus4 C♯add9 C♯m(add9) C♯6/9 C♯9 C♯maj9 C♯m9 C♯11 C♯m11 C♯13 C♯7♭9 C♯7♯9 C♯7♯5 C♯7♭5