C13♭9

6-note dominant 13th flat 9 on CC, C♯, E, G, A, A♯.

Press to hear the chord strummed low to high.

A dominant thirteenth with a flat ninth — the sweet thirteenth over the biting flat nine, a hallmark of bebop turnarounds.

The notes

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

Interval formula

DegreeNoteWhat it is
1Croot
♭9C♯flat ninth
3Emajor third
5Gperfect fifth
13Athirteenth
♭7A♯flat seventh (dominant)

The formula reads in semitones above the root (C): 1, ♭9, 3, 5, 13, ♭7. A voicing may leave a tone out — often the fifth — but never adds one from outside this set.

Ukulele fingerings · 4

312
open position
31
open position
3fr1243
from fret 3
6fr1412
from fret 6

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 C chords

13♭9 chords on every root