Guitar chord Ab13(b9) - diagrams and theory

Ab 13(b9) guitar chord shapes

In Ab13(b9) (Ab thirteenth flat nine) the notes are Ab, C, Eb, Gb, Bbb, Db and F, built by stacking thirds on Ab up to the thirteenth.

The Bbb is the flat ninth, written with a double flat so that every letter name appears once. It sounds like A, a half step above the root. When you improvise, try the Ab Half-Whole scale, which alternates half and whole steps and covers every chord tone except the eleventh.

A dominant chord like this one usually resolves to the chord a fourth above Ab, which is Db.

Ab 13th with flat 9th guitar chord is also written as Ab13(b9), Ab13b9 or Ab13-9.

Notes that compose the Ab 13(b9) chord:

Ab C Eb Gb Bbb Db F

Tones in the Dominant Thirteen Flat Nine chord:

Formula: 1 3 5 b7 b9 11 13

Play This Chord With Other Roots

C 13(b9) | D 13(b9) | E 13(b9) | F 13(b9) | G 13(b9) | A 13(b9) | B 13(b9) | C#13(b9) | D#13(b9) | F#13(b9) | G#13(b9) | A#13(b9) | Ab13(b9) | Bb13(b9) | Db13(b9) | Eb13(b9) | Gb13(b9)

Giancarlo Facoetti, founder of FaChords Guitar

Created by

Giancarlo Facoetti

Giancarlo is a musician (teaching guitar since 2000), software engineer, AI consultant and published researcher

FAQ

What notes are in Ab13(b9)?

Ab13(b9) contains Ab, C, Eb, Gb, Bbb, Db and F. Those are the root, major third, perfect fifth, minor seventh, flat ninth, eleventh and thirteenth.

Why is there a double flat in Ab13(b9)?

Counting nine letters up from Ab lands on B, and the major ninth is Bb. Lowering it by a half step gives Bbb, which sounds like A but is named by its role.

Is Ab13(b9) the same chord as G#13(b9)?

Yes, they are the same sound. G#13(b9) spells it G#, B#, D#, F#, A, C# and E#, so the flat name is the one with fewer sharps to read.

Which scale fits Ab13(b9)?

The Ab half-whole scale contains every chord tone except the eleventh, Db. It supplies the flat ninth, so the scale and chord share the same tension.