Ab9 — Ab dominant ninth chord

A dominant seventh chord with the ninth added. The ninth is a whole tone above the root in the octave above it.

1 = Ab
9 = Bb
3 = C
5 = Eb
b7 = Gb

Symbol: Ab9
Root: Ab
Quality: Dominant ninth
Family: extended
Notes: Ab Bb C Eb Gb
Degree formula: 1 9 3 5 b7
Semitones from the root: 0 2 4 7 10
Distinct pitch classes: 5
Interval structure: Stacked from the root: 2 semitones, 2 semitones, 3 semitones, 3 semitones
Notation: Written 9. The standard extension of a dominant chord in funk, soul and jazz.
Key: Ab · Ab major / F minor key signature

Formula

The chord tones in order from the root, with the interval each one forms above it.

Degree	Note	Semitones	Interval from the root
1	Ab	0	Perfect unison
9	Bb	2	Major second
3	C	4	Major third
5	Eb	7	Perfect fifth
b7	Gb	10	Minor seventh

Inversions

An inversion is the same set of notes with a different one in the bass. The last column gives the distance of each note above the bass note, in semitones.

Inversion	Bass note	Degree in the bass	Notes above the bass	Semitones above the bass
root position	Ab	1	Ab – Bb – C – Eb – Gb	0 2 4 7 10
first inversion	Bb	9	Bb – C – Eb – Gb – Ab	0 2 5 8 10
second inversion	C	3	C – Eb – Gb – Ab – Bb	0 3 6 8 10
third inversion	Eb	5	Eb – Gb – Ab – Bb – C	0 3 5 7 9
fourth inversion	Gb	b7	Gb – Ab – Bb – C – Eb	0 2 4 6 9

Inversion

Bass note

Degree in the bass

Notes above the bass

Semitones above the bass

root position

Ab – Bb – C – Eb – Gb

0 2 4 7 10

first inversion

Bb – C – Eb – Gb – Ab

0 2 5 8 10

second inversion

C – Eb – Gb – Ab – Bb

0 3 6 8 10

third inversion

Eb – Gb – Ab – Bb – C

0 3 5 7 9

fourth inversion

Gb – Ab – Bb – C – Eb

0 2 4 6 9

Playable voicings

These shapes were found by searching the fretboard of a standard-tuned guitar (E A D G B E) rather than copied from a chord book. The search allows every string to sound or to be muted, rejects any shape with a muted string between two sounding strings, rejects any shape whose fretted notes span more than four frets (a five-fret window), requires every chord tone to be present, and then sorts what remains with root-position shapes first and the most compact, lowest shapes next. The shapes shown are the first six of that ordering; other orderings are possible at the same frets.

#	Shape (low string first)	Notes	Degrees	Bass	Span (frets)	Sounding strings
1	4-3-4-3-4-4 (6→1)	Ab C Gb Bb Eb Ab	1 3 b7 9 5 1	Ab	1	6
2	4-3-4-3-4-2 (6→1)	Ab C Gb Bb Eb Gb	1 3 b7 9 5 b7	Ab	2	6
3	4-6-4-5-4-6 (6→1)	Ab Eb Gb C Eb Bb	1 5 b7 3 5 9	Ab	2	6
4	4-1-1-1-1-2 (6→1)	Ab Bb Eb Ab C Gb	1 9 5 1 3 b7	Ab	3	6
5	4-1-1-3-1-2 (6→1)	Ab Bb Eb Bb C Gb	1 9 5 9 3 b7	Ab	3	6
6	4-3-1-3-1-2 (6→1)	Ab C Eb Bb C Gb	1 3 5 9 3 b7	Ab	3	6

Shape numbers run from the lowest string to the highest, so the left-hand number is the sixth string (low E) in standard tuning. Multiple shapes are listed because a chord can be voiced several ways, and because a lower position is not always the better sounding one.

Related chords and scales

KeyEverything in Abscale, chords and neck map for this root
ScaleAb mixolydianthe scale this chord comes from
ChordAb7the seventh chord underneath it

Everything in Ab · All chords

KeyKey of AbAb Bb C Db Eb F G · Ab major / F minor
ScaleAb mixolydian7 notes · 1 2 3 4 5 6 b7
ChordAb7 — Dominant seventh1 3 5 b7 · Ab C Eb Gb
ChordAb11 — Dominant eleventh1 9 3 11 5 b7 · Ab Bb C Db Eb Gb
ChordAb13 — Dominant thirteenth1 9 3 5 13 b7 · Ab Bb C Eb F Gb
ChordAbm11 — Minor eleventh1 9 b3 11 5 b7 · Ab Bb Cb Db Eb Gb
DegreesAb — degree mapAb major and natural minor · frets 0–22
Neck mapAb — note mapAb major · frets 0–22 · Ab Bb C Db Eb F G

Everything in this key: Ab · Chords · Theory Atlas