Also written C7, C or C Dominant 7th
C 7th contains C, E, G, and B♭. This open shape uses one finger and has no muted strings, making it a quick first dominant chord.
The same three notes, with a different one in the bass.
C 7th is built from the formula 1, 3, 5, ♭7. The minor 7th interval from C to B♭ creates the dominant sound, and the diminished 5th between E and B♭ adds tension. Compare with C major to hear the difference.
C 7th is the V chord in F major, resolving to F major in progressions like F–B♭–C–F (I–IV–V–I). Use it in blues, jazz, and swing for a classic dominant pull. It also works over C major and C 5th riffs.
The open C7 shape is the easiest and works well for fast changes. The C7/E inversion at frets 3-4-3-3 puts E in the bass and suits fingerpicking. The C7/B♭ inversion at frets 9-10-8-10 has B♭ in the bass for a darker sound.
C 7th is played in open position as 0 0 0 1: index finger on the A string at fret 1. The G, C and E strings ring open.
Tip — The open C7 shape has no barre and no muted strings, but the index finger must fret the A string cleanly without touching the E string.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | open | — | G (5) |
| 3 (C) | open | — | C (1) |
| 2 (E) | open | — | E (3) |
| 1 (A) | 1 | 1 | B♭ (♭7) |
C 7th is played at the 3rd fret as 3 4 3 3: index finger on the G string at fret 3, pinky finger on the C string at fret 4, middle finger on the E string at fret 3 and ring finger on the A string at fret 3.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 3 | 1 | B♭ (♭7) |
| 3 (C) | 4 | 4 | E (3) |
| 2 (E) | 3 | 2 | G (5) |
| 1 (A) | 3 | 3 | C (1) |
C 7th is played at the 5th fret as 5 7 6 7: index finger on the G string at fret 5, ring finger on the C string at fret 7, middle finger on the E string at fret 6 and pinky finger on the A string at fret 7.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 5 | 1 | C (1) |
| 3 (C) | 7 | 3 | G (5) |
| 2 (E) | 6 | 2 | B♭ (♭7) |
| 1 (A) | 7 | 4 | E (3) |
C 7th is played at the 8th fret as 9 10 8 10: middle finger on the G string at fret 9, ring finger on the C string at fret 10, index finger on the E string at fret 8 and pinky finger on the A string at fret 10.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 9 | 2 | E (3) |
| 3 (C) | 10 | 3 | B♭ (♭7) |
| 2 (E) | 8 | 1 | C (1) |
| 1 (A) | 10 | 4 | G (5) |
C 7th is played in open position as 0 4 6 3: middle finger on the C string at fret 4, ring finger on the E string at fret 6 and index finger on the A string at fret 3. The G string rings open.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | open | — | G (5) |
| 3 (C) | 4 | 2 | E (3) |
| 2 (E) | 6 | 3 | B♭ (♭7) |
| 1 (A) | 3 | 1 | C (1) |
C 7th is written as C7. It is also called Dominant 7th or Major Minor 7th.
C7 has a minor 7th (B♭), while Cmaj7 has a major 7th (B). The minor 7th gives C7 its dominant, bluesy tension. Cmaj7 sounds smoother and more resolved.
The lowest sounding note is the C string, which is open. The open G string is higher in pitch due to reentrant tuning. This makes the chord root position rather than an inversion.
Yes, C7 often substitutes for C major in blues and rock to add a dominant flavor. In F major progressions, C7 strengthens the pull back to F. In other contexts, the added B♭ may clash with the melody.