Also written C♯7, C♯ or C♯ Dominant 7th
C♯ 7th is built from C♯, E♯, G♯, and B. The 9th-fret shape stretches the pinky to fret 11 on the A string, making clean fretting the main challenge.
The same three notes, with a different one in the bass.
C♯ 7th uses the formula 1, 3, 5, ♭7. The minor 7th interval between C♯ and B gives the chord its dominant quality, and the diminished 5th between E♯ and B adds tension. Compare it with C♯ major, which omits the ♭7.
C♯ 7th is the V chord in F♯ major, so it appears in progressions like F♯–B–C♯–F♯ (I–IV–V–I). Its dominant pull suits blues, rock, and funk bass lines that resolve to F♯.
The 9th-fret shape has C♯ in the bass and is the most direct voicing. The C♯7/G♯ inversion at the 4th fret puts G♯ in the bass for a smoother transition from F♯ major, while the C♯7/B inversion at the 7th fret leads into F♯ major by step.
C♯ 7th is played at the 9th fret as 9 11 9 10: index finger on the E string at fret 9, pinky finger on the A string at fret 11, middle finger on the D string at fret 9 and ring finger on the G string at fret 10.
Tip — The pinky must reach from the 9th fret to the 11th fret on the A string while the other fingers hold their frets cleanly.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 9 | 1 | C♯ (1) |
| 3 (A) | 11 | 4 | G♯ (5) |
| 2 (D) | 9 | 2 | B (♭7) |
| 1 (G) | 10 | 3 | E♯ (3) |
C♯ 7th is played at the 3rd fret as 4 4 3 4: middle finger on the E string at fret 4, ring finger on the A string at fret 4, index finger on the D string at fret 3 and pinky finger on the G string at fret 4.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 4 | 2 | G♯ (5) |
| 3 (A) | 4 | 3 | C♯ (1) |
| 2 (D) | 3 | 1 | E♯ (3) |
| 1 (G) | 4 | 4 | B (♭7) |
C♯ 7th is played at the 6th fret as 7 8 6 6: barre your index finger across fret 6, middle finger on the E string at fret 7 and ring finger on the A string at fret 8.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 7 | 2 | B (♭7) |
| 3 (A) | 8 | 3 | E♯ (3) |
| 2 (D) | 6 | 1 (barre) | G♯ (5) |
| 1 (G) | 6 | 1 (barre) | C♯ (1) |
C♯ 7th is written as C♯7, or C#7 in ASCII. It is also spelled D♭ in enharmonic notation for the same sounding root.
C♯ 7th adds a B note, the minor 7th, to the C♯ major triad. That B creates a tritone with E♯, giving C♯ 7th its dominant tension.
C♯ 7th is built on the fifth degree of F♯ major, where it functions as the dominant. The name comes from that dominant function, not from the chord's internal intervals.