A9 Chord (Dominant 9th)

Dominant 9th extends dom7 with a 9th — root, 3rd, 5th, flat 7th, 9th — a dominant chord with extra colour instead of extra tension. The notes of A9 are A, C#, E, G, B.

Funk and soul horn-section harmony lives here: it still pulls like a dominant chord but sits richer and rounder than plain dom7.

A9 voicings on guitar

Every playable, root-in-the-bass grip standard tuning offers, computed from the chord’s own formula — not a fixed shape library.

Stab it rhythmically on the "and" of a beat, funk-style, rather than holding it — this chord wants to be played, not sustained.

Formula and intervals

R - 3 - 5 - b7 - 2 — 5 notes.

Scales that fit A9

Every scale below contains all of this chord’s notes — safe territory to improvise in over it.

• A Mixolydian

Other extended on A

• A6 (Major 6th)
• Aadd9 (Add 9)
• Amaj9 (Major 9th)
• Am9 (Minor 9th)
• A11 (Dominant 11th)
• Amaj13 (Major 13th)