Tools / Chords / A♭ augmented

A♭ augmented chord on bass (A♭aug)

Also written A♭aug or A♭+

A♭ augmented contains A♭, C, and E. The 2nd-fret shape stacks three notes across adjacent strings, so the left hand stays compact but the stretch is real.

2nd fret4-3-2-×

Positions on the neck1 of 5

How it’s built

A♭1Root

C3Major 3rd

E♯5Augmented 5th

Formula 1, 3, ♯5

Positions on the neck1 of 5

Inversions

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

Root positionA♭–C–EA♭augBass A♭

First inversionC–E–A♭A♭aug/CBass C

Second inversionE–A♭–CA♭aug/EBass E

Why it sounds like that

A♭ augmented is built from the formula 1, 3, ♯5. The augmented 5th from A♭ to E gives the chord its tense, unresolved quality. Compare it with A♭ major, which uses E♭ instead.

What goes wrong with A♭ augmented?

Letting the ring finger flatten onto the A string, which deadens the C.
Allowing the open G string to ring, adding a note outside the chord.
Pressing the middle finger too far from the fret, causing the A string to buzz.

When to use it

A♭ augmented works as a passing chord in A♭ major, often moving to A♭ major or A♭ 5th. Its unstable sound suits rock, blues, and funk lines that need a brief lift before resolving.

Changing to and from A♭ augmented

Move to A♭ major by lowering the E on the D string one fret to E♭ while keeping the other fingers in place.
Slide the shape up one fret to the 3rd fret to reach A augmented.

Which voicing to use

The 2nd-fret position keeps A♭ in the bass for a root-position sound. The A♭aug/C inversion at the 1st fret puts C on the bottom, which softens the chord's drive and works well when the bass line moves stepwise.

How do you play an A♭ augmented chord on bass?

2nd fret

Intermediate● On the diagram

A♭ augmented is played at the 2nd fret as 4 3 2 ×: ring finger on the E string at fret 4, middle finger on the A string at fret 3 and index finger on the D string at fret 2. The G string stays muted.

Tip — The ring finger reaches to the 4th fret on the E string while the index stays at the 2nd fret on the D string, creating a two-fret stretch.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	4	3	A♭ (1)
3 (A)	3	2	C (3)
2 (D)	2	1	E (♯5)
1 (G)	muted	—	—

9th fret

Intermediate

A♭ augmented is played at the 9th fret as × 11 10 9: ring finger on the A string at fret 11, middle finger on the D string at fret 10 and index finger on the G string at fret 9. The E string stays muted.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	muted	—	—
3 (A)	11	3	A♭ (1)
2 (D)	10	2	C (3)
1 (G)	9	1	E (♯5)

A♭aug/C inversion · fret 1

Intermediate

A♭ augmented is played at the 1st fret as × 3 2 1: ring finger on the A string at fret 3, middle finger on the D string at fret 2 and index finger on the G string at fret 1. The E string stays muted.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	muted	—	—
3 (A)	3	3	C (3)
2 (D)	2	2	E (♯5)
1 (G)	1	1	A♭ (1)

A♭aug/C inversion · fret 6

Intermediate

A♭ augmented is played at the 6th fret as 8 7 6 ×: ring finger on the E string at fret 8, middle finger on the A string at fret 7 and index finger on the D string at fret 6. The G string stays muted.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	8	3	C (3)
3 (A)	7	2	E (♯5)
2 (D)	6	1	A♭ (1)
1 (G)	muted	—	—

A♭aug/C inversion · fret 13

Intermediate

A♭ augmented is played at the 13th fret as × 15 14 13: ring finger on the A string at fret 15, middle finger on the D string at fret 14 and index finger on the G string at fret 13. The E string stays muted.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	muted	—	—
3 (A)	15	3	C (3)
2 (D)	14	2	E (♯5)
1 (G)	13	1	A♭ (1)

Common questions

How is A♭ augmented written?

A♭ augmented is written as A♭+ or A♭aug. The ASCII root is Ab. It is also spelled G♯ in enharmonic notation for the same sounding root.

What is the difference between A♭ augmented and A♭ major?

A♭ augmented raises the fifth from E♭ to E. That single change makes the chord sound tense and unresolved, while A♭ major sounds stable.

Can I play A♭ augmented higher on the neck?

Yes, the 9th-fret position uses the same shape on the A, D, and G strings. It gives a brighter register but the same chord tones.

String

Fret

Finger

Note

4 (E)

A♭ (1)

3 (A)

C (3)

2 (D)

E (♯5)

1 (G)

muted

—

String

Fret

Finger

Note

4 (E)

muted

—

3 (A)

A♭ (1)

2 (D)

C (3)

1 (G)

E (♯5)

String

Fret

Finger

Note

4 (E)

muted

—

3 (A)

C (3)

2 (D)

E (♯5)

1 (G)

A♭ (1)

String

Fret

Finger

Note

4 (E)

C (3)

3 (A)

E (♯5)

2 (D)

A♭ (1)

1 (G)

muted

—

String

Fret

Finger

Note

4 (E)

muted

—

3 (A)

C (3)

2 (D)

E (♯5)

1 (G)

A♭ (1)