- A9
- Amaj7
A9 Guitar Chord
Everything about the A Dominant 9 chord: How to play it, what it's built from, the chords it pairs with, and examples of pros using it in real performances.
NotesA • C♯ • E • G • B
Difficulty
Moderate
E-string root barre shape
What is the A9 chord?
The A9 chord, or A Dominant 9, is a five-note chord built from an A major triad (A, C#, E) plus a minor seventh (G) and a major ninth (B)—that distinctive ninth interval is what gives it its name and character. It has a bright, open, slightly bluesy flavor with an unresolved tension that begs to move somewhere else, making it perfect for blues, funk, soul, and jazz where it often appears as a secondary dominant or color chord. The most common voicing is a barre chord played from the fifth fret, which sits at moderate difficulty—not beginner-friendly, but well within reach for players with a few months of practice under their belt.
Notes & Intervals
A9 spells out as A (1) · B (M3) · C# (P5) · E (m7) · G (M9). The minor seventh and the major ninth together create the chord's signature color—that blend of bluesy tension and bright, open extension that makes dominant 9ths so appealing in jazz, funk, and soul.
Where It Lives
A9 thrives in jazz, funk, R&B, and blues as a dominant chord (V chord pulling toward resolution) or as a color chord in grooves. It's equally at home in modern pop and soul, where its blend of tension and brightness adds sophistication without heaviness.
A9 vs. A7
A7 contains A · C# · E · G (root, major third, perfect fifth, minor seventh), while A9 adds the major ninth (B) on top. That added ninth lifts the chord into a more sophisticated, open sound—less raw and more colorful than the simpler A7.
Mood & Character
A9 feels cool, sophisticated, and slightly edgy—confident without being harsh. Reach for it when you want to add swagger and depth to a groove, or when you need a dominant chord that sounds modern and open rather than traditional.
Voicings for A9
Four ways to play it using the same five notes. Pick a voicing below to hear it on the fretboard.
- NotesA • E • G • C♯ • E • BDifficultyModerate
E-string root barre shape
Progressions that use A9
Hear how the chord works in context of songs.
Learn to play A9 from the experts
Handpicked lessons from TrueFire courses that lean on this chord.
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Frequently asked questions for A9
The A9 chord contains five notes: A (the root), C# (a major third above A), E (a perfect fifth), G (a minor seventh), and B (a major ninth). The formula is 1 · M3 · P5 · m7 · M9. The ninth is the note B, which is the same pitch as the second note of the A major scale but played an octave higher. This gives the chord its bright, open sound.
A9 and A7 are closely related. A7 contains A, C#, E, and G (root, major third, perfect fifth, and minor seventh). A9 adds one more note: B, which is the major ninth. That extra B note gives A9 a richer, more colorful quality. Both are dominant seventh chords, but the ninth adds complexity and is often used in jazz, funk, and blues to create a more sophisticated harmonic flavor.
Yes, A9 is played as a barre chord starting at the 5th fret, using the notation 5-7-5-6-5-7. Because it's a barre shape, you can move it up or down the neck to play other ninth chords. For example, moving the entire shape up two frets (to the 7th fret) gives you B9. This movable quality makes it a practical tool once you master the fingering.
A9 is called a dominant ninth chord because it's built on a dominant seventh (A7) with an added ninth. In music theory, a dominant chord is the fifth chord of a key—in the key of D major, A is the fifth note, so A9 naturally wants to resolve to D. The dominant seventh has a strong pull toward resolution, and adding the ninth intensifies that quality. This makes A9 especially useful in blues, jazz, and funk progressions where you want movement and tension.
The standard barre fingering uses your index finger to bar across the 5th fret on strings 1, 3, and 5 (high E, G, and low E). Your middle finger plays the 6th fret on the D string, your ring finger plays the 7th fret on the B string, and your pinky plays the 7th fret on the high E string. This creates the shape 5-7-5-6-5-7. It's a moderate difficulty chord because the barre requires pressure, but once you develop finger strength, it becomes comfortable and movable across the neck.