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A minor 7th flat 5th chord on bass (Am7♭5)
Also called or written Am7♭5, A or A Half Diminished Minor 7
A minor 7th flat 5th contains A, C, E♭ and G. The 5th-fret shape spreads four fingers across two frets, demanding a wide left-hand stretch.
How it is built
Formula 1, ♭3, ♭5, ♭7
- Root positionA–C–E♭–GAm7♭55-6-5-5
- First inversionC–E♭–G–AAm7♭5/Cno shape on this instrument
- Second inversionE♭–G–A–CAm7♭5/E♭11-12-10-12
- Third inversionG–A–C–E♭Am7♭5/G3-3-1-2
How do you play an A minor 7th flat 5th chord on bass?
A minor 7th flat 5th is played at the 5th fret as 5 6 5 5: index finger on the E string at fret 5, pinky finger on the A string at fret 6, middle finger on the D string at fret 5 and ring finger on the G string at fret 5.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 5 | 1 | A (1) |
| 3 (A) | 6 | 4 | E♭ (♭5) |
| 2 (D) | 5 | 2 | G (♭7) |
| 1 (G) | 5 | 3 | C (♭3) |
AdvancedThe wide stretch between the index finger on the 4th string and the pinky on the 3rd string at the 5th fret is the hardest part.
Am7♭5/E♭ inversion
A minor 7th flat 5th is played at the 10th fret as 11 12 10 12: middle finger on the E string at fret 11, ring finger on the A string at fret 12, index finger on the D string at fret 10 and pinky finger on the G string at fret 12.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 11 | 2 | E♭ (♭5) |
| 3 (A) | 12 | 3 | A (1) |
| 2 (D) | 10 | 1 | C (♭3) |
| 1 (G) | 12 | 4 | G (♭7) |
Am7♭5/G inversion · fret 1
A minor 7th flat 5th is played at the 1st fret as 3 3 1 2: ring finger on the E string at fret 3, pinky finger on the A string at fret 3, index finger on the D string at fret 1 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) | 3 | 4 | C (♭3) |
| 2 (D) | 1 | 1 | E♭ (♭5) |
| 1 (G) | 2 | 2 | A (1) |
Am7♭5/G inversion · fret 13
A minor 7th flat 5th is played at the 13th fret as 15 15 13 14: ring finger on the E string at fret 15, pinky finger on the A string at fret 15, index finger on the D string at fret 13 and middle finger on the G string at fret 14.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 15 | 3 | G (♭7) |
| 3 (A) | 15 | 4 | C (♭3) |
| 2 (D) | 13 | 1 | E♭ (♭5) |
| 1 (G) | 14 | 2 | A (1) |
Why it sounds like that
A minor 7th flat 5th is built from the formula 1, ♭3, ♭5, ♭7. The diminished 5th between A and E♭ gives the chord its tense, unresolved quality. Raising the ♭5 to a perfect 5th produces A minor 7th, the closest stable contrast.
What goes wrong with A minor 7th flat 5th?
- Letting the pinky collapse and mute the 2nd string.
- Fretting the 1st string with the ring finger too far from the fret, causing a buzz.
- Allowing the index finger to touch the 3rd string and deaden the A.
When to use it
A minor 7th flat 5th functions as the ii chord in G natural minor and the vii chord in B♭ major. Use it in minor-key jazz and blues lines where the half-diminished colour leads to a dominant. It pairs naturally with A minor and A 5th.
Changing to and from A minor 7th flat 5th
- Sliding the shape down two frets to the 3rd fret gives G minor 7th flat 5th.
- Sliding the shape up one fret to the 6th fret gives B♭ minor 7th flat 5th.
Which voicing to use
The 5th-fret root position keeps A in the bass for a grounded sound. The Am7♭5/E♭ inversion at the 11th fret places the diminished 5th in the bass, creating a darker, less stable feel. Choose the Am7♭5/G inversion when the bass line needs to descend to G.
Other A chords
Common questions
How is A minor 7th flat 5th written?
A minor 7th flat 5th is written as Am7♭5, and it is also called Half Diminished Minor 7.
What is the difference between A minor 7th flat 5th and A diminished?
A minor 7th flat 5th adds a minor 7th to the diminished triad. A diminished chord has only the root, ♭3 and ♭5.
Why does A minor 7th flat 5th sound unstable?
The tritone between A and E♭ creates tension that wants to resolve. This instability makes the chord useful as a passing harmony.