Sevenths
C♯ dominant 7th chord
Bluesy tension that pulls strongly toward the chord a 5th below.
C♯7 is the V7 chord in F♯ major. In minor keys: V7 in F♯ minor.
- Notes
- C♯E♯G♯B
- Formula
- 135♭7
- Built from
- root · major 3rd · perfect 5th · minor 7th
How to play C♯7
About the C♯ dominant 7th chord
C♯7 is the V7 of F♯, and it often appears as a “secondary dominant” — the chord that leads into F♯m — in songs in A and E.
Playing it
On guitar, C♯7 has an open-position shape, x43404, using four fingers alongside the open strings. Don’t strum the low E string.
On piano, C♯7 has two black keys (C♯ and G♯) and two white keys.
On ukulele the usual C♯7 shape is 1112, using four fingers.
Related chords
Take away the root and the other three notes form E♯dim (E♯ G♯ B) — so you can think of C♯7 as E♯dim with C♯ added underneath.
Move a single note and C♯7 becomes a different chord: drop the B for C♯, raise B to B♯ for C♯maj7, lower E♯ to E for C♯m7 and lower B to A♯ for C♯6.
Where you’ll hear it
You’ll find C♯7 in common progressions such as C♯7–F♯7–G♯7 (the 12-bar blues in C♯ major) and G♯m7–C♯7–F♯maj7 (the jazz cadence in F♯ major).
Notice the E♯ in C♯7 (C♯ E♯ G♯ B): each note of the chord takes its own letter (C–E–G–B), so the major 3rd has to be written E♯ rather than F — the same key on a piano, spelled to fit the chord.
