C♯7♭9 / D♭7♭9

5-note dominant 7th flat 9 on C♯ / D♭C♯, D, F, G♯, B.

Press to hear the chord strummed low to high.

A dominant seventh with a flat ninth on top — dark and tense, a signature sound over a minor resolution.

The notes

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

Interval formula

DegreeNoteWhat it is
1C♯root
♭9Dflat ninth
3Fmajor third
5G♯perfect fifth
♭7Bflat seventh (dominant)

The formula reads in semitones above the root (C♯): 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

234
open position
4fr1234
from fret 4
7fr3241
from fret 7
9fr1324
from fret 9

Ukulele fingerings · 4

1324
open position
4fr1324
from fret 4
7fr1324
from fret 7
10fr1324
from fret 10

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♯ / D♭ chords

7♭9 chords on every root