Guitar arpeggio

A Dominant 9 Guitar Arpeggio

A Dominant 9 is a five-note arpeggio built from A, C#, E, G, and B. It is also commonly called A Dominant Ninth and A9. Use it to study chord tones, interval formulas, and guitar fretboard positions.

Chord tones
A, C#, E, G, B
Formula
1 3 5 b7 9
Semitones
0 4 7 10 14
Chord symbols
A9
Also called
A Dominant NinthA9

How to read this arpeggio

The chord tones are shown as pitch classes first. In the fretboard tool, square markers represent A root notes, while circular markers represent the remaining tones in the arpeggio.

Use the interactive fretboard to locate the A root notes and connect the remaining dominant 9 chord tones across standard tuning.

This same arpeggio shape is also commonly called A Dominant Ninth or A9.

Chord construction and defining tones

3C#
b7G
9B

A dominant 9 is defined by 3 (C#), b7 (G), and 9 (B). The dominant guide tones remain intact while the ninth adds an upper extension.

Harmonic use

Use this arpeggio over A9, dominant funk and blues harmony, or a V chord that includes the natural ninth.

Practice this arpeggio on guitar

  1. Play the A Dominant 9 arpeggio from one A root to the next in at least two fretboard positions, saying each note name and interval degree aloud.
  2. Play 3 (C#), b7 (G), and 9 (B) as a rootless three-note group in several positions, then add the root and fifth.
  3. Outline A9, emphasize the ninth, and resolve the third and flat seventh into the next chord.

Fretboard diagram

A Dominant 9 Guitar Arpeggio fretboard diagram in standard tuning
A Dominant 9 Guitar Arpeggio fretboard diagram in standard tuning.

Open this arpeggio in the fretboard tool

Start with A Dominant 9 loaded, then adjust tuning, labels, colors, fret count, and orientation.

Open in interactive fretboard

Arpeggio diagrams by tuning