Ab Dominant Ninth Chord
Chord Tones: Ab Dominant Ninth Chord
Symbol: 9 — Formula: 1-3-5-♭7-9
| Degree | Note | Frequency (A=440, Equal) |
|---|---|---|
| 1 | Ab | 415.305 Hz |
| 3 | C | 261.626 Hz |
| 5 | Eb | 311.127 Hz |
| ♭7 | Gb | 369.994 Hz |
| 9 | Bb | 466.164 Hz |
Chord Notation
| Notation Type | Symbol / Value |
|---|---|
| Lead Sheet Symbol | Ab9 |
| 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 | Ab – C – Eb – Gb – Bb | Ab | Ab Dominant Ninth Chord |
| First Inversion | C – Eb – Gb – Bb – Ab | C | Ab Dominant Ninth Chord/C |
| Second Inversion | Eb – Gb – Bb – Ab – C | Eb | Ab Dominant Ninth Chord/Eb |
| Third Inversion | Gb – Bb – Ab – C – Eb | Gb | Ab Dominant Ninth Chord/Gb |
| Fourth Inversion | Bb – Ab – C – Eb – Gb | Bb | Ab Dominant Ninth Chord/Bb |
Harmonic Function
The Ab dominant ninth chord commonly functions as the submediant (♭VI) in C minor or subdominant in E♭ major. 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 Ab 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 Ab 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 |
|---|---|---|---|
| Ab | 415.305 Hz | 417.657 Hz | 418.601 Hz |
| C | 261.626 Hz | 260.740 Hz | 261.626 Hz |
| Eb | 311.127 Hz | 309.026 Hz | 313.951 Hz |
| Gb | 369.994 Hz | 371.251 Hz | 367.911 Hz |
| Bb | 466.164 Hz | 463.538 Hz | 470.926 Hz |
Scales Containing the Ab Dominant Ninth Chord
These scales include the Ab Dominant Ninth Chord as a diatonic or characteristic chord: