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A♭ diminished 7th chord on bass (A♭dim7)
Also called or written A♭dim7 or A♭°7
A♭ diminished 7th contains A♭, C♭, E♭♭, and G♭♭. Its 3rd fret position requires a wide stretch across all four strings.
How it is built
Formula 1, ♭3, ♭5, ♭♭7
- Root positionA♭–C♭–E♭♭–G♭♭A♭dim74-5-3-4
- First inversionC♭–E♭♭–G♭♭–A♭A♭dim7/C♭7-8-6-7
- Second inversionE♭♭–G♭♭–A♭–C♭A♭dim7/E♭♭10-11-9-10
- Third inversionG♭♭–A♭–C♭–E♭♭A♭dim7/G♭♭1-2-0-1
How do you play an A♭ diminished 7th chord on bass?
A♭ diminished 7th is played at the 3rd fret as 4 5 3 4: middle finger on the E string at fret 4, pinky finger on the A string at fret 5, index finger on the D string at fret 3 and ring finger on the G string at fret 4.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 4 | 2 | A♭ (1) |
| 3 (A) | 5 | 4 | E♭♭ (♭5) |
| 2 (D) | 3 | 1 | G♭♭ (6) |
| 1 (G) | 4 | 3 | C♭ (♭3) |
AdvancedThe span from the index finger on the 2nd string to the pinky on the 3rd string requires significant finger independence.
A♭dim7/C♭ inversion
A♭ diminished 7th is played at the 6th fret as 7 8 6 7: middle finger on the E string at fret 7, pinky finger on the A string at fret 8, index finger on the D string at fret 6 and ring finger on the G string at fret 7.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 7 | 2 | C♭ (♭3) |
| 3 (A) | 8 | 4 | G♭♭ (6) |
| 2 (D) | 6 | 1 | A♭ (1) |
| 1 (G) | 7 | 3 | E♭♭ (♭5) |
A♭dim7/E♭♭ inversion
A♭ diminished 7th is played at the 9th fret as 10 11 9 10: middle finger on the E string at fret 10, pinky finger on the A string at fret 11, index finger on the D string at fret 9 and ring finger on the G string at fret 10.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 10 | 2 | E♭♭ (♭5) |
| 3 (A) | 11 | 4 | A♭ (1) |
| 2 (D) | 9 | 1 | C♭ (♭3) |
| 1 (G) | 10 | 3 | G♭♭ (6) |
A♭dim7/G♭♭ inversion · open position
A♭ diminished 7th is played in open position as 1 2 0 1: index finger on the E string at fret 1, ring finger on the A string at fret 2 and middle finger on the G string at fret 1. The D string rings open.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 1 | 1 | G♭♭ (6) |
| 3 (A) | 2 | 3 | C♭ (♭3) |
| 2 (D) | open | — | E♭♭ (♭5) |
| 1 (G) | 1 | 2 | A♭ (1) |
A♭dim7/G♭♭ inversion · fret 12
A♭ diminished 7th is played at the 12th fret as 13 14 12 13: middle finger on the E string at fret 13, pinky finger on the A string at fret 14, index finger on the D string at fret 12 and ring finger on the G string at fret 13.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 13 | 2 | G♭♭ (6) |
| 3 (A) | 14 | 4 | C♭ (♭3) |
| 2 (D) | 12 | 1 | E♭♭ (♭5) |
| 1 (G) | 13 | 3 | A♭ (1) |
Why it sounds like that
A♭ diminished 7th is built from the intervals 1, ♭3, ♭5, and ♭♭7 — a stack of three minor 3rds. The diminished 5th between A♭ and E♭♭ gives the chord its unstable, tense quality. Compare it with A♭ minor 7th flat 5th, which raises the seventh from G♭♭ to G♭.
What goes wrong with A♭ diminished 7th?
- Letting the index finger flatten and mute the 1st string.
- Pressing too hard with the pinky, causing the 3rd string to buzz.
- Failing to keep the middle finger perpendicular to the fretboard.
When to use it
A♭ diminished 7th often appears as a passing chord in jazz and classical music. It can resolve to A♭ minor 7th flat 5th or B♭ major. A♭ diminished 7th suits dramatic transitions and chromatic bass lines.
Changing to and from A♭ diminished 7th
- Sliding the shape down two frets to the 1st fret gives F♯ diminished 7th.
- Sliding the shape up one fret to the 4th fret gives A diminished 7th.
Which voicing to use
The 3rd fret position keeps A♭ as the lowest note, giving a clear root-position sound. The A♭dim7/B inversion places C♭ in the bass, creating a darker, less stable voicing. Choose the root position for foundational bass lines and inversions for smoother voice leading.
Other A♭ chords
Common questions
How is A♭ diminished 7th written?
A♭ diminished 7th is written as A♭°7 or A♭dim7. The ASCII root is Ab, so you can type Abdim7. It is also spelled G♯ in enharmonic notation for the same sounding root.
What is the difference between A♭ diminished 7th and A♭ minor 7th flat 5th?
A♭ diminished 7th has a double-flatted seventh (G♭♭), while A♭ minor 7th flat 5th has a minor seventh (G♭). The diminished 7th chord is more dissonant and symmetrical.
Why does A♭ diminished 7th sound so tense?
A♭ diminished 7th contains two diminished 5th intervals: A♭–E♭♭ and C♭–G♭♭. These tritones create a strong pull toward resolution.