C add9 chord (Cadd9)
The C add9 chord (Cadd9) adds one note to the major triad: C, E, G and D (root, major third, perfect fifth and major ninth).
It is the Iadd9 in C major and the IVadd9 in G major; since it contains the whole major triad, it can take its place to give it another color.
Below: voicings, notes on the fretboard, ukulele, piano, inversions and progressions.
How to play C add9 on guitar
There is 1 guitar voicing.
Frets from the 6th string to the 1st: x = not played, 0 = open string.
- Voicing 1: x-3-2-0-3-0, open position, with C in the bass (fingers x-3-2-0-4-0).
Notes of the C add9 chord on the fretboard
C add9 has 4 notes: C, E, G and D. This is where they fall on each string, from the nut to the 12th fret (fret number in parentheses):
- String 6 (E): E (0) · G (3) · C (8) · D (10) · E (12)
- String 5 (A): C (3) · D (5) · E (7) · G (10)
- String 4 (D): D (0) · E (2) · G (5) · C (10) · D (12)
- String 3 (G): G (0) · C (5) · D (7) · E (9) · G (12)
- String 2 (B): C (1) · D (3) · E (5) · G (8)
- String 1 (E): E (0) · G (3) · C (8) · D (10) · E (12)
Formula and intervals of C add9
Its formula is 1-3-5-9; in semitones from the root, 0-4-7-14.
- C: Root, the note that gives the chord its name
- E: Major third (M3), 4 semitones above C
- G: Perfect fifth (P5), 7 semitones above C
- D: Major ninth (M9), 14 semitones above C
C add9 on ukulele
- Ukulele (G C E A): 0-2-0-3; it sounds G, D, E and C.
C add9 on piano
- Keys: C4, E4, G4 and D5.
Inversions of C add9
Each inversion puts a different note in the bass.
- Root position: C, E, G and D, with C in the bass.
- First inversion (Cadd9/E): E, G, C and D, with E in the bass.
- Second inversion (Cadd9/G): G, C, E and D, with G in the bass.
Keys that use C add9
C add9 appears in 6 major and minor keys.
| Key | Degree | Function |
|---|---|---|
| C major (no sharps or flats) | Iadd9 | Tonic |
| G major (1 sharp) | IVadd9 | Subdominant |
| F major (1 flat) | Vadd9 | Dominant |
| A minor (no sharps or flats) | IIIadd9 | Mediant |
| E minor (1 sharp) | VIadd9 | Submediant |
| D minor (1 flat) | VIIadd9 | Subtonic |
Progressions with C add9
- Pop progression with add9 color in C major (Iadd9–V–vi–IV): Cadd9 – G – Am – F
Frequently asked questions
What notes are in the C add9 chord?
C, E, G and D: root, major third, perfect fifth and major ninth. Its formula is 1-3-5-9.
Which keys use C add9?
Mainly as the Iadd9 in C major and the IVadd9 in G major. In total it appears in 6 major and minor keys.
What kind of chord is C add9?
It is a major triad with one extra note, which adds color without changing its function. In C add9 you hear C, E, G and D (root, major third, perfect fifth and major ninth).