Explore chords · Bass
B 7th chord on bass (B7)
Also called or written B7, B, B Dominant 7th or B Major Minor 7th
B 7th is built from B, D♯, F♯, and A. The 7th-fret shape requires a wide pinky stretch on the A string, making clean fretting the main challenge.
How it is built
Formula 1, 3, 5, ♭7
How do you play a B 7th chord on bass?
B 7th is played at the 7th fret as 7 9 7 8: index finger on the E string at fret 7, pinky finger on the A string at fret 9, middle finger on the D string at fret 7 and ring finger on the G string at fret 8.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 7 | 1 | B (1) |
| 3 (A) | 9 | 4 | F♯ (5) |
| 2 (D) | 7 | 2 | A (♭7) |
| 1 (G) | 8 | 3 | D♯ (3) |
AdvancedThe pinky must reach from the 7th fret to the 9th fret on the A string while the other fingers hold their frets cleanly.
B7/F♯ inversion · fret 1
B 7th is played at the 1st fret as 2 2 1 2: middle finger on the E string at fret 2, ring finger on the A string at fret 2, index finger on the D string at fret 1 and pinky finger on the G string at fret 2.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 2 | 2 | F♯ (5) |
| 3 (A) | 2 | 3 | B (1) |
| 2 (D) | 1 | 1 | D♯ (3) |
| 1 (G) | 2 | 4 | A (♭7) |
B7/F♯ inversion · fret 13
B 7th is played at the 13th fret as 14 14 13 14: middle finger on the E string at fret 14, ring finger on the A string at fret 14, index finger on the D string at fret 13 and pinky finger on the G string at fret 14.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 14 | 2 | F♯ (5) |
| 3 (A) | 14 | 3 | B (1) |
| 2 (D) | 13 | 1 | D♯ (3) |
| 1 (G) | 14 | 4 | A (♭7) |
B7/A inversion
B 7th is played at the 4th fret as 5 6 4 4: ring finger on the E string at fret 5, pinky finger on the A string at fret 6, index finger on the D string at fret 4 and middle finger on the G string at fret 4.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 5 | 3 | A (♭7) |
| 3 (A) | 6 | 4 | D♯ (3) |
| 2 (D) | 4 | 1 | F♯ (5) |
| 1 (G) | 4 | 2 | B (1) |
Why it sounds like that
B 7th uses the formula 1, 3, 5, ♭7. The minor 7th interval between B and A gives the chord its dominant quality, and the diminished 5th between D♯ and A adds tension. Compare it with B major, which omits the ♭7.
What goes wrong with B 7th?
- Letting the pinky collapse and buzz the A string at fret 9.
- Allowing the ring finger to touch the D string and mute it.
- Striking the open E string instead of fretting it at the 7th fret.
When to use it
B 7th is the V chord in E major, so it appears in progressions like E–A–B–E (I–IV–V–I). Its dominant pull suits blues, rock, and funk bass lines that resolve to E.
Changing to and from B 7th
- Move to E major by lifting the pinky and shifting the index and middle fingers down one string each.
- Slide the shape down two frets to the 5th fret to play A 7th.
Which voicing to use
The 7th-fret shape has B in the bass and is the most direct voicing. The B7/F♯ inversion at the 2nd fret puts F♯ in the bass for a smoother transition from E major, while the B7/A inversion at the 5th fret leads into E major by step.
Other B chords
Common questions
How does B 7th differ from B major?
B 7th adds an A note, the minor 7th, to the B major triad. That A creates a tritone with D♯, giving B 7th its dominant tension.
Why is B 7th called a dominant 7th chord?
B 7th is built on the fifth degree of E major, where it functions as the dominant. The name comes from that dominant function, not from the chord's internal intervals.
Can B 7th be played with a barre?
The 7th-fret shape uses individual fingers, not a barre. The B7/F♯ inversion at the 2nd fret also uses separate fingers, so no barre is required.