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A♭ add 9 chord on bass (A♭add9)
Also called or written A♭add9, A♭ or A♭ Add 9th
A♭ add 9 contains A♭, C, E♭, and B♭. This advanced voicing at the 6th fret requires a wide left-hand stretch.
A♭add9/B♭ inversionfrom fret 5
How it is built
Formula 1, 3, 5, 9
- Root positionA♭–C–E♭–B♭A♭add9no shape on this instrument
- First inversionC–E♭–B♭–A♭A♭add9/Cno shape on this instrument
- Second inversionE♭–B♭–A♭–CA♭add9/E♭no shape on this instrument
- Third inversionB♭–A♭–C–E♭A♭add9/B♭6-6-6-5
How do you play an A♭ add 9 chord on bass?
A♭ add 9 is played at the 5th fret as 6 6 6 5: middle finger on the E string at fret 6, ring finger on the A string at fret 6, pinky finger on the D string at fret 6 and index finger on the G string at fret 5.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 6 | 2 | B♭ (2) |
| 3 (A) | 6 | 3 | E♭ (5) |
| 2 (D) | 6 | 4 | A♭ (1) |
| 1 (G) | 5 | 1 | C (3) |
AdvancedThe one-fret offset between the index finger on fret 5 and the other fingers on fret 6 requires precise finger independence.
Why it sounds like that
A♭ add 9 uses the formula 1, 3, 5, 9. The major 2nd between A♭ and B♭ adds a floating quality to the major triad. Compare it with A♭ major, which omits the ninth.
What goes wrong with A♭ add 9?
- Letting the index finger flatten and mute the D string.
- Fretting the G string at fret 6 instead of fret 5, which changes the ninth to a major third.
When to use it
A♭ add 9 can replace A♭ major in the I–IV–V–I progression A♭–D♭–E♭–A♭. Its airy sound suits jazz, pop, and R&B bass lines. Use it over A♭ major or A♭ 5th.
Changing to and from A♭ add 9
- Sliding the shape down two frets to the 4th fret gives F♯ add 9.
- From A♭ add 9, move the index finger up one fret to the 6th fret while keeping the other fingers in place to reach A add 9.
Which voicing to use
The A♭add9/B♭ inversion places B♭, the ninth, in the bass. This voicing works when the bass needs to lead into C or A♭.
Other A♭ chords
Common questions
How is A♭ add 9 written?
A♭ add 9 is written as A♭add9 or A♭. On a keyboard, the root is typed as Ab. It is also spelled G♯ in enharmonic notation for the same sounding root.
How does A♭ add 9 differ from A♭ suspended 2nd?
A♭ suspended 2nd replaces the major third with the major second, giving A♭–B♭–E♭. A♭ add 9 keeps the major third and adds the second on top, so it sounds more resolved.
Is A♭ add 9 easier to play on a 5-string bass?
A 5-string bass with a low B string allows the same shape to be played five frets lower, reducing the stretch. On a 4-string, the 6th fret position is necessary.