Sevenths
C♯ diminished 7th chord
Symmetrical and very tense — every note is a minor 3rd apart.
C♯dim7 is the vii°7 chord in D minor.
- Notes
- C♯EGB♭
- Formula
- 1♭3♭5𝄫7
- Built from
- root · minor 3rd · diminished 5th · diminished 7th
How to play C♯dim7
About the C♯ diminished 7th chord
Playing it
There’s no open-string way to play C♯dim7 on guitar with the root in the bass, so the standard shape is a barre across the 9th fret (9-10-11-9-11-9).
On piano, C♯dim7 has two black keys (C♯ and B♭) and two white keys.
On ukulele the usual C♯dim7 shape is 0101, using two fingers.
Related chords
Take away the root and the other three notes form Edim (E G B♭) — so you can think of C♯dim7 as Edim with C♯ added underneath.
C♯dim7 is symmetrical — its notes are evenly spaced — so Edim7, Gdim7 and B♭dim7 contain exactly the same notes. There are only three different-sounding diminished 7th chords in all.
Move a single note and C♯dim7 becomes a different chord: drop the B♭ for C♯dim, raise G to G♯ for C♯m6 and raise B♭ to B for C♯m7♭5.
