Chords

Ab Dominant ninth

Ab · C · Eb · Gb · Bb

The dominant ninth — a dominant seventh with a major ninth added. Fuller, and a shade less aggressive.

Ab Dominant ninth

Ab · C · Eb · Gb · Bb

Play it on your instrument
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Voicings on the piano
VoicingNotesPlay it on your instrument
Closed, root positionAb3 · C4 · Eb4 · Gb4 · Bb4
Open (drop 2)Gb3 · Ab3 · C4 · Eb4 · Bb4
ShellAb3 · C4 · Gb4
RootlessC3 · Gb3 · Bb3

Tap a key or a fret to hear it.

Anatomy

Ab Dominant ninth (Ab9) contains the notes Ab · C · Eb · Gb · Bb, each with a role measured as an interval from the root.

Read on: how triads are built · seventh chords · extensions

Inversions

An inversion of Ab Dominant ninth puts a chord tone other than Ab in the bass; the name after the slash is that bass note.

Where it lives

The keys and the scales Ab Dominant ninth belongs to.

In which keys

Ab Dominant ninth is diatonic to 2 keys; the numeral is its degree and the label its harmonic function.

Extensions beyond the seventh count when every note sits in the key.

Scales that contain it

Ab Dominant ninth fits inside these scales, each built on Ab.

Understanding the Ab Dominant ninth chord

Names and symbols

Ab9 is the chord symbol for Ab Dominant ninth.

add9, 9 and maj9 are three different chords. add9 adds a ninth to a plain triad with no seventh; 9 is a dominant seventh with a ninth; maj9 is a major seventh with a ninth.

Ab Dominant ninth and G# Dominant ninth are the same sound spelled two ways; both have a page here, and each links to the other. G# Dominant ninth

How it is built

On Ab it is Ab · C · Eb · Gb · Bb, stacking 1P · 3M · 5P · 7m · 9M. The tritone that drives the dominant is still there; the ninth simply adds width above it.

How it is used

It is the standard funk and soul dominant — the James Brown chord, usually voiced without the root so the bass can own it. In a ii–V–I it makes the V richer without weakening the resolution.

Common questions

What notes are in Ab9?
Ab9 contains Ab · C · Eb · Gb · Bb. Name any set of notes with the chord identifier.
How is a 9 chord different from a 7?
It adds the major ninth above the dominant seventh. The tritone and the resolution are unchanged; the chord is just wider.
Do I need to play all five notes?
No. The fifth is usually dropped first, and in a band the root as well — the third, seventh and ninth carry the sound.
What notes are in the Ab Dominant ninth chord?
The Ab Dominant ninth chord contains the notes Ab · C · Eb · Gb · Bb: the root Ab with the intervals 1P, 3M, 5P, 7m, 9M stacked above it. Play them together for the chord or one after another for an arpeggio. The lowest note is normally Ab, but any chord tone can take the bass in an inversion.
What intervals make up the Ab Dominant ninth chord?
Measured from Ab, the Ab Dominant ninth chord stacks the intervals 1P, 3M, 5P, 7m, 9M. The quality of the third and of the seventh, if there is one, is what gives the chord its character; the rest of the notes colour it. Every interval in the formula links to its own page, with its sound.

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