C#9 guitar chord
The standard grips this chord is usually shown with.
- Tap a note to hear it
- Arrows change position
- Fingers, notes or intervals
- Play the chord
About C#9 — 1st inversion
C#9 is C#, E#, G#, B and D# — C#7 with the ninth stacked on top.
It sounds bright and full, still clearly pulling. The ninth adds height without softening the tritone underneath it, which is why funk and soul comp on this rather than on a plain 7.
C#9 notes and formula
| C# | E# | G# | B | D# |
|---|---|---|---|---|
| 1 | 3 | 5 | ♭7 | 9 |
Dominant — the same pull as a 7, with more colour.
Also written C#dom9 or C# dominant 9. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play C#9
C#9 in 1st inversion puts E# in the bass instead of C#, the 3rd of the chord. The notes are the same; what changes is what the bass line does, which is most of why you would reach for it — it lets the lowest voice move by step where the root would have jumped.
One of C#9’s 8 common shapes does this: 13-x-11-13-12-11.
Start with 9898xx — no barre. None of the shapes for C#9 uses an open string, so every one of them is movable; the lowest sits at the 3rd fret. 5 of the 8 need a barre. Together they cover the neck from the 3rd fret to the 13th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x43444 | 3rd fret | C#, root position | G# | barred |
| x66667 | 6th fret | D#, 9th in the bass | B | barred |
| 966867 | 6th fret | C#, root position | B | barred |
| 9898xx | 8th fret | C#, root position | D# | all fretted |
| 9-11-9-8-9-11 | 8th fret | C#, root position | D# | barred |
| 9-11-9-10-9-11 | 9th fret | C#, root position | D# | barred |
| x-x-11-10-12-11 | 10th fret | C#, root position | D# | all fretted |
| 13-x-11-13-12-11 | 11th fret | E#, 1st inversion | D# | all fretted |
The same notes rebuilt from scratch give 3 shell, 12 drop 2, 8 drop 3 and 13 rootless voicings, each on its own page.
Tensions. A shell of C#9, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (F##), the b13 (A) and the 13 (A#).
How to use C#9
C#9 is the V of F#, and that is where it goes if it goes anywhere: the third and the flat seventh are a tritone apart, and both resolve by a semitone into F#.
Voice by voice, C#9 → F#. 2 voices move by a semitone, and one note is common to both chords.
| In C#9 | Moves | In F# |
|---|---|---|
| C#, the root | stays where it is | C#, the fifth |
| E#, the major third | rises a semitone | F#, the root |
| G#, the fifth | falls a whole tone | F#, the root |
| B, the flat seventh | falls a semitone | A#, the major third |
| D#, the ninth | falls a whole tone | C#, the fifth |
In which keys. Every note of C#9 belongs to Eb minor (the ♭VII) and F# major (the V, the dominant).
What to play over C#9
Every note of C#9 is in C# mixolydian and C# lydian dominant.
Chords near C#9
Change one note of C#9 and you have C#maj9 (the flat seventh becomes a major seventh), C#m9 (the major third becomes a minor third), C#add9 (drop the flat seventh), C#69 (the flat seventh becomes a sixth), C#7 (drop the ninth) or C#9b5 (the fifth becomes a flat fifth).
C#9 is a dominant chord — root, major third, fifth, minor seventh. Dominant seventh chords on every root.
On C#9’s sound and use this page follows Mark Levine, The Jazz Theory Book (Sher Music, 1995). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.