C Dominant Ninth Chord
Chord Tones: C Dominant Ninth Chord
Symbol: 9 — Formula: 1-3-5-♭7-9
| Degree | Note | Frequency (A=440, Equal) |
|---|---|---|
| 1 | C | 261.626 Hz |
| 3 | E | 329.628 Hz |
| 5 | G | 391.995 Hz |
| ♭7 | A# | 466.164 Hz |
| 9 | D | 293.665 Hz |
Chord Notation
| Notation Type | Symbol / Value |
|---|---|
| Lead Sheet Symbol | C9 |
| All Common Symbols | 9 |
| Interval Formula | 1-3-5-♭7-9 |
| Harmonic Category | tense |
Roman numeral (e.g. I, IV, V) and Nashville Number notation are key-dependent. See Keys pages for chord function within specific keys.
Inversions
| Inversion | Notes (low to high) | Bass Note | Slash Notation |
|---|---|---|---|
| Root Position | C – E – G – A# – D | C | C Dominant Ninth Chord |
| First Inversion | E – G – A# – D – C | E | C Dominant Ninth Chord/E |
| Second Inversion | G – A# – D – C – E | G | C Dominant Ninth Chord/G |
| Third Inversion | A# – D – C – E – G | A# | C Dominant Ninth Chord/A# |
| Fourth Inversion | D – C – E – G – A# | D | C Dominant Ninth Chord/D |
Harmonic Function
The C dominant ninth chord commonly functions as the tonic (I) in C major/minor. Its harmonic role varies by key — in major keys it provides stable harmonic grounding.
The dominant ninth chord extends the dominant seventh with a ninth, adding color and richness to one of music's most harmonically active chords. Essential in jazz, blues, and funk.
Common Progressions
The C Dominant Ninth Chord frequently appears in these progression patterns (shown in Roman numeral notation relative to key):
V9-Iii9-V9-I
Songs Featuring the Dominant Ninth Chord
Well-known songs where the C Dominant Ninth Chord — or this chord type — plays a prominent role:
- Purple Haze – Jimi Hendrix
- What's Going On – Marvin Gaye
- Superstition – Stevie Wonder
Tuning Frequencies Across Temperaments
Frequencies shown at A=440 Hz. View full temperament data for any note.
| Note | Equal Temp. | Pythagorean | Just Intonation |
|---|---|---|---|
| C | 261.626 Hz | 260.740 Hz | 261.626 Hz |
| E | 329.628 Hz | 330.001 Hz | 327.032 Hz |
| G | 391.995 Hz | 391.111 Hz | 392.438 Hz |
| A# | 466.164 Hz | 463.538 Hz | 470.926 Hz |
| D | 293.665 Hz | 293.332 Hz | 294.329 Hz |
Scales Containing the C Dominant Ninth Chord
These scales include the C Dominant Ninth Chord as a diatonic or characteristic chord: