C#9 Chord
C#9 is a dominant seventh plus D sharp, the ninth. Its full spelling has five different notes, so a practical guitar or ukulele grip may leave out a less essential chord tone.
- Notes: C sharp-E sharp-G sharp-B-D sharp
- Symbol: C#9
- V9 in F# major
- Seventh and ninth
C#9
How to play a C#9 chord
Notes: C# - E# - G# - B - D#C#9
Root position
C# - E# - G# - B - D#1st inversion
E# - G# - B - D# - C#2nd inversion
G# - B - D# - C# - E#3rd inversion
B - D# - C# - E# - G#
Where does C#9 belong?
In F# major, C#9 extends the V7 chord before it resolves to the tonic.
Play the role cards to hear how its surrounding chords change the job it does; Diatonic Chords explains the basic numbered roles.
- Dominant with a ninthV9
A V7 with the ninth on top: the same pull to F#, a fuller sound.
F#BC#9V9F# - Funk and blues homeI9
In funk and blues this is a home chord that never has to resolve.
C#9I9F#9C#9G#9
Progressions to try
- F#BC#9F#
C#9 is V9 in F# major; its seventh keeps the dominant pull while the ninth adds another voice.
- C#9F#9C#9G#9
Treat the repeated C#9 as a blues home chord, then hear the other ninth chords answer it.
Which shape should you use?
On guitar, start with 9-11-9-10-9-11, a barre at the 9th fret.
On ukulele, start with 4314, played at the 1st fret. 6576 gives a higher version.
On piano, spread the five-note spelling across both hands: C sharp-E sharp-G sharp-B-D sharp. Move C sharp up an octave to reach the first inversion, E sharp-G sharp-B-D sharp-C sharp; the notes remain the same while the lowest voice changes.
What are the inversions?
The first four notes, C sharp-E sharp-G sharp-B, form the dominant seventh. D sharp adds the ninth.
- Root position: C sharp-E sharp-G sharp-B-D sharp, with C sharp lowest.
- First inversion: E sharp-G sharp-B-D sharp-C sharp, written C#9/E# if E sharp is lowest in the whole arrangement.
- Second inversion: G sharp-B-D sharp-C sharp-E sharp, written C#9/G# if G sharp is lowest in the whole arrangement.
- Third inversion: B-D sharp-C sharp-E sharp-G sharp, written C#9/B if B is lowest in the whole arrangement.
- Fourth inversion: D sharp-C sharp-E sharp-G sharp-B, written C#9/D# if D sharp is lowest in the whole arrangement.
A slash chord names the note in the bass, not merely the lowest note under one hand. Chord Inversions shows how to read that distinction.
How does C#9 differ from C#7?
Remove the ninth, D sharp, and the remaining notes form C#7. The seventh stays, so both chords can still pull toward the same tonic. Try that one-note change on piano, then use the comparer to hear it in the full chord. See C#7 for the other chord's full spelling and roles.
C#9
C# - E# - G# - B - D#C#7
C# - E# - G# - B