C♯ diminished chord
The vii° of D major: three notes that lean straight into D.
- How it sounds
- Tense and unstable. Both gaps are three frets, C♯ to E and E to G, so the fifth sits a fret flat and nothing in the chord settles. There’s no open grip. The lowest of its four grips is the G-root form, at the 3rd fret.
- Where it lives
- The vii° of D major, the ii° of B minor and the vii° of D harmonic minor. Rarely a chord you stay on: it passes between chords, or stands in for A7 on the way to D, since it’s A7 without the A. Jazz, gospel and classical harmony, where passing chords are everyday. Rock and pop use it much less.
Voicings across the neck
C♯, E and G are shown in four places on the neck. Every grip uses four strings, so one of the three notes is doubled, and each takes its name from the string its root sits on. Mute the other two. The lowest is the G-root form at the 3rd fret, and the highest the D-root form at the 11th.
- High E string: G at fret 3
- B string: E at fret 5
- G string: C♯ at fret 6
- D string: G at fret 5
- A string: not played
- Low E string: not played
- High E string: not played
- B string: E at fret 5
- G string: C♯ at fret 6
- D string: G at fret 5
- A string: C♯ at fret 4
- Low E string: not played
- High E string: not played
- B string: not played
- G string: E at fret 9
- D string: C♯ at fret 11
- A string: G at fret 10
- Low E string: C♯ at fret 9
- High E string: E at fret 12
- B string: C♯ at fret 14
- G string: G at fret 12
- D string: C♯ at fret 11
- A string: not played
- Low E string: not played
Formula
| Intervals | Notes | Semitones |
|---|---|---|
| R · m3 · d5: what each interval does in a chord | C♯ · E · G | 3 + 3 |
C♯ diminished is a root, a minor third and a diminished fifth: C♯, E and G. Three then three is what makes it diminished, two minor thirds stacked, so the fifth lands a fret below a perfect one. Raise G a fret to G♯ and you get C♯ minor.
In these keys and scales
C♯ diminished turns up in six scales on the site, and it’s home in none of them. In D major it’s the vii°, a fret below D. In B minor and B harmonic minor it’s the ii°. D harmonic minor and D melodic minor both raise their seventh note to C♯, so it’s their vii° too, and in E melodic minor it’s the vi°. The numeral beside each scale names the job, and the name opens that scale’s page.
| Family | Scales |
|---|---|
| Major | |
| Natural minor | |
| Harmonic minor | |
| Melodic minor |
Progressions
C♯dim hardly ever ends a phrase, and in all three of these it’s on its way somewhere. In vii°–I it resolves up a fret, C♯ to D. In I–vii°–vi it’s the middle step of a bass line walking down, D, C♯, B. In ii°–V–i it opens the minor cadence, and F♯ carries it the rest of the way to Bm.