C#7#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#7#9 — 2nd inversion
C#7#9 is C#, E#, G#, B and E — C#9 with the ninth raised a semitone.
It sounds gritty and contradictory. The minor third sounding over the major third; every guitarist knows it as the Hendrix chord.
C#7#9 notes and formula
| C# | E# | G# | B | E |
|---|---|---|---|---|
| 1 | 3 | 5 | ♭7 | ♯9 |
Altered dominant — dominant function with a blues third on top.
Also written C#7(#9), C#7+9 or C#7♯9. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play C#7#9
C#7#9 in 2nd inversion puts G# in the bass instead of C#, the 5th 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#7#9’s 9 common shapes does this: x-11-11-10-12-12.
Start with x43420 — no barre and 1 open string. 1 of the 9 shapes here sits in open position. 4 of the 9 need a barre. Together they cover the neck from the 2nd fret to the 12th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x43420 | open position | C#, root position | E | 1 open string |
| x4345x | 3rd fret | C#, root position | E | all fretted |
| x76667 | 6th fret | D##, 9th in the bass | B | barred |
| 9899xx | 8th fret | C#, root position | E | barred |
| x89999 | 8th fret | E#, 1st inversion | C# | barred |
| 9-11-9-10-9-12 | 9th fret | C#, root position | E | barred |
| 9-11-9-10-12-12 | 9th fret | C#, root position | E | all fretted |
| x-x-11-10-12-12 | 10th fret | C#, root position | E | all fretted |
| x-11-11-10-12-12 | 10th fret | G#, 2nd inversion | E | all fretted |
The same notes rebuilt from scratch give 3 shell, 12 drop 2, 8 drop 3, 13 rootless and 6 open string voicings, each on its own page.
Tensions. A shell of C#7#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#7#9
C#7#9 is a dominant with its tension raised, so it still points at F# — harder than a plain seventh does, because the altered tones sit a semitone from where they are going.
Voice by voice, C#7#9 → F#. 2 voices move by a semitone, and one note is common to both chords.
| In C#7#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 |
| E, the sharp ninth | rises a whole tone | F#, the root |
What to play over C#7#9
Every note of C#7#9 is in C# half-whole diminished.
Chords near C#7#9
Change one note of C#7#9 and you have C#m7 (drop the major third), C#m9 (the major third becomes a ninth), C#7 (drop the minor third), C#9 (the minor third becomes a ninth) or C#7b9 (the minor third becomes a flat ninth).
C#7#9 is an altered chord — a dominant seventh with its fifth or ninth moved. Altered dominant chords on every root.
On C#7#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.