B9 (dominant ninth)

5-note dominant 9th on BB, C♯, D♯, F♯, A.

Press to hear the chord strummed low to high.

A dominant seventh extended with the ninth — funky and full, the sound of a James Brown horn stab.

The notes

Pitches taken from the first fingering below — click any note to open its frequency page.

Interval formula

DegreeNoteWhat it is
1Broot
9C♯ninth
3D♯major third
5F♯perfect fifth
♭7Aflat seventh (dominant)

The formula reads in semitones above the root (B): 1, 9, 3, 5, ♭7. A voicing may leave a tone out — often the fifth — but never adds one from outside this set.

Guitar fingerings · 4

2334
open position
4fr411312
from fret 4
7fr131214
from fret 7
8fr2143
from fret 8

Ukulele fingerings · 4

23
open position
5fr2314
from fret 5
8fr1234
from fret 8
11fr1312
from fret 11

Read a diagram top-down: the thick bar is the nut, dots are where to press (the number is which finger), means play the open string, means don't play it. A bar across strings is a barre.

Other B chords

9 (dominant ninth) chords on every root