Tools / Chords / A♭ add 9

A♭ add 9 chord on bass (A♭add9)

Also 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♭ inversion6-6-6-5

How it’s built

A♭1Root

C3Major 3rd

E♭5Perfect 5th

B♭99th

Formula 1, 3, 5, 9

Inversions

The same three notes, with a different one in the bass.

Root positionA♭–C–E♭–B♭A♭add9Bass A♭

First inversionC–E♭–B♭–A♭A♭add9/CBass C

Second inversionE♭–B♭–A♭–CA♭add9/E♭Bass E♭

Third inversionB♭–A♭–C–E♭A♭add9/B♭Bass B♭

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♭.

How do you play an A♭ add 9 chord on bass?

A♭add9/B♭ inversion

Intermediate● On the diagram

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.

Tip — The one-fret offset between the index finger on fret 5 and the other fingers on fret 6 requires precise finger independence.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	6	2	B♭ (9)
3 (A)	6	3	E♭ (5)
2 (D)	6	4	A♭ (1)
1 (G)	5	1	C (3)

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.

String

Fret

Finger

Note

4 (E)

B♭ (9)

3 (A)

E♭ (5)

2 (D)

A♭ (1)

1 (G)

C (3)