The C♯ Add 9 chord is a four-note chord made up of C♯, E♯, G♯, and D♯. It is built from a root, major third, perfect fifth, and major ninth.
Construction
C♯ Add 9 = Root + Major 3rd + Perfect 5th + Major 2nd = C♯ · E♯ · G♯ · D♯
| Note | Interval | Degree |
|---|---|---|
| C♯ | Root | 1 |
| E♯ | Major 3rd | 3 |
| G♯ | Perfect 5th | 5 |
| D♯ | Major 2nd | 2 |
C♯ Add 9 Inversions
| Position | Notes |
|---|---|
| Root Position | C♯ – E♯ – G♯ – D♯ |
| 1st Inversion | E♯ – G♯ – D♯ – C♯ |
| 2nd Inversion | G♯ – D♯ – C♯ – E♯ |
| 3rd Inversion | D♯ – C♯ – E♯ – G♯ |
Key Signature
A chord has no key signature of its own, but the C♯ Add 9 is the tonic (I) chord of C# Major, whose key signature has 7 sharps (F♯, C♯, G♯, D♯, A♯, E♯, B♯).
F♯C♯G♯D♯A♯E♯B♯
Order of sharps
Sharps are added to a key signature in a fixed order. Each new sharp key adds the next sharp on the list.
F♯C♯G♯D♯A♯E♯B♯
Mnemonic: Father Charles Goes Down And Ends Battle
Chords in the Key of C♯ Major
These are the triads built on each degree of the C♯ major scale:
Same Notes, Other Names
The notes C♯ – E♯ – G♯ – D♯ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell:
C♯ Add 9 — Frequently Asked Questions
What is the C♯ Add 9 chord on piano?
The C♯ Add 9 chord contains the notes C♯ – E♯ – G♯ – D♯. On piano, play these notes together to sound the chord.
What notes are in the C# Add 9 chord?
C# Add 9 is built from the C# root. Check the interactive keyboard above for exact notes and fingering.
How is the C# Add 9 chord used in music?
C# Add 9 appears in jazz, pop, and classical contexts. Its sound depends on the chord quality (Add 9).
What is the fingering for C# Add 9?
See the fingering chart above. Right hand typically uses thumb on root. Left hand uses pinky on root.
What are the inversions of C# Add 9?
Use the inversion buttons above to see each inversion with notes, fingering, and staff notation.