Article
How to Read Guitar Chord Diagrams
Learn how to read guitar chord diagrams quickly. Understand dots, numbers, Xs, Os, and finger positions so you can play any chord chart at sight.
A7♯9/B♯ guitar shapes
Popular fretboard positions with fingering suggestions
Showing 8 of 20 playable shapes
About the chord
A dominant 7th sharp 9th / B♯ (4th inversion)
The A dominant 7th sharp 9th dominant 7th sharp 9th chord introduces a sharp ninth B♯, creating a bluesy, expressive tension. The clash between the major third C♯ and sharp ninth B♯ gives it a powerful, gritty sound used in jazz, funk, and rock. With B♯ in the bass, this voicing functions as the 4th inversion of A dominant 7th sharp 9th.
Root note: A
Bass note: B♯
Chord tones: 5
Playable shapes: 20
Chord tones
AC♯EGB♯
Notes & Intervals
Each note below shows how the chord is built from its root. This is the theory layer underneath the fretboard shapes.
A Unison (Root) 1
The root anchors the chord and defines its tonal center.
C♯ Major Third 3
This note defines the chord's major quality and brings brightness to the sound.
E Perfect Fifth 5
The fifth reinforces stability and gives the chord its strong harmonic frame.
G Minor Seventh ♭7
The minor seventh adds bluesy or jazzy tension that wants to move onward.
B♯ Augmented Ninth ♯9
This tone contributes color and function inside the chord voicing.
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