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A 7th chord on bass (A7)
Also called or written A7, A, A Dominant 7th or A Major Minor 7th
A 7th is built from A, C♯, E, and G. The 5th-fret shape stretches the pinky to fret 7 on the A string, making clean fretting the main challenge.
How it is built
Formula 1, 3, 5, ♭7
- Root positionA–C♯–E–GA75-7-5-6
- First inversionC♯–E–G–AA7/C♯no shape on this instrument
- Second inversionE–G–A–C♯A7/E12-12-11-12
- Third inversionG–A–C♯–EA7/G3-4-2-2
How do you play an A 7th chord on bass?
A 7th is played at the 5th fret as 5 7 5 6: index finger on the E string at fret 5, pinky finger on the A string at fret 7, middle finger on the D string at fret 5 and ring finger on the G string at fret 6.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 5 | 1 | A (1) |
| 3 (A) | 7 | 4 | E (5) |
| 2 (D) | 5 | 2 | G (♭7) |
| 1 (G) | 6 | 3 | C♯ (3) |
AdvancedThe pinky must reach from the 5th fret to the 7th fret on the A string while the other fingers hold their frets cleanly.
A7/E inversion
A 7th is played at the 11th fret as 12 12 11 12: middle finger on the E string at fret 12, ring finger on the A string at fret 12, index finger on the D string at fret 11 and pinky finger on the G string at fret 12.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 12 | 2 | E (5) |
| 3 (A) | 12 | 3 | A (1) |
| 2 (D) | 11 | 1 | C♯ (3) |
| 1 (G) | 12 | 4 | G (♭7) |
A7/G inversion
A 7th is played at the 2nd fret as 3 4 2 2: ring finger on the E string at fret 3, pinky finger on the A string at fret 4, index finger on the D string at fret 2 and middle finger on the G string at fret 2.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 3 | 3 | G (♭7) |
| 3 (A) | 4 | 4 | C♯ (3) |
| 2 (D) | 2 | 1 | E (5) |
| 1 (G) | 2 | 2 | A (1) |
Why it sounds like that
A 7th uses the formula 1, 3, 5, ♭7. The minor 7th interval between A and G gives the chord its dominant pull, and the diminished 5th between C♯ and G adds tension. Compare it with A major, which omits the ♭7.
What goes wrong with A 7th?
- Letting the pinky collapse and buzz the A string at fret 7.
- Allowing the ring finger to touch the D string and mute it.
- Striking the open E string instead of fretting it at the 5th fret.
When to use it
A 7th is the V chord in D major, so it appears in progressions like D–G–A–D (I–IV–V–I). Its dominant quality suits blues, rock, and funk bass lines that need a strong resolution.
Changing to and from A 7th
- Move to D major by lifting the pinky and shifting the index and middle fingers down one string each.
- Slide the shape down two frets to the 3rd fret to play G 7th.
Which voicing to use
The 5th-fret shape has A in the bass and is the most direct voicing. The A7/E inversion at the 12th fret puts E in the bass for a smoother transition from D major, while the A7/G inversion at the 3rd fret leads into D major by step.
Other A chords
Common questions
How does A 7th differ from A major?
A 7th adds a G note, the minor 7th, to the A major triad. That G creates a tritone with C♯, giving A 7th its dominant tension.
Why is A 7th called a dominant 7th chord?
A 7th is built on the fifth degree of D major, where it functions as the dominant. The name comes from that dominant function, not from the chord's internal intervals.
Can A 7th be played with a barre?
The 5th-fret shape uses individual fingers, not a barre. The A7/E inversion at the 12th fret also uses separate fingers, so no barre is required.