Chord and FretA9 — dominant ninth
Notes in A9: A – C# – E – G – BFormula: 1 – 3 – 5 – b7 – 9In the formula, the numbers count steps of the major scale starting from the note that names the chord; "b" lowers a half step, "#" raises one — and a slash names the bass note.
The 9 is the dominant chord with the ninth. It keeps the dominant function and adds color and breadth.
The same chord on all four instruments
Where to use it: Blues, funk, choro and broader dominants.
Every region of the neck hides more shapes of A9. In Chord and Fret, you hear every shape strummed string by string, in each instrument's own voice; compare positions with their difficulty marked; and set a capo — the diagrams redraw above it. Start free. Unlock everything with Pro. Plays offline.
See the whole neck in Chord and Fret →Part of the Extended family.