A♭ Sixth-Ninth Chord
Chord Tones: A♭ Sixth-Ninth Chord
Symbol: 6/9 — Formula: 1-3-5-6-9
| Degree | Note | Frequency (A=440, Equal) |
|---|---|---|
| 1 | A♭4 | 415.305 Hz |
| 3 | C4 | 261.626 Hz |
| 5 | E♭4 | 311.127 Hz |
| 6 | F4 | 349.228 Hz |
| 9 | B♭4 | 466.164 Hz |
Chord Notation
| Notation Type | Symbol / Value |
|---|---|
| Lead Sheet Symbol | A♭6/9 |
| All Common Symbols | 6/9 |
| Interval Formula | 1-3-5-6-9 |
| Harmonic Category | bright |
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 | A♭4 – C4 – E♭4 – F4 – B♭4 | A♭ | A♭ Sixth-Ninth Chord |
| First Inversion | C4 – E♭4 – F4 – B♭4 – A♭4 | C | A♭ Sixth-Ninth Chord/C |
| Second Inversion | E♭4 – F4 – B♭4 – A♭4 – C4 | E♭ | A♭ Sixth-Ninth Chord/E♭ |
| Third Inversion | F4 – B♭4 – A♭4 – C4 – E♭4 | F | A♭ Sixth-Ninth Chord/F |
| Fourth Inversion | B♭4 – A♭4 – C4 – E♭4 – F4 | B♭ | A♭ Sixth-Ninth Chord/B♭ |
Harmonic Function
The A♭ sixth 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 6/9 chord adds both the sixth and ninth to a major triad without a seventh. It has a rich, colorful sound with a jazz and bossa nova flavor, often used as a final tonic chord. The A♭ Sixth-Ninth Chord specifically contains 5 notes: A♭, C, E♭, F, B♭ (formula: 1-3-5-6-9). On piano, Ab-rooted chords use a combination of black and white keys that creates a relaxed hand shape, favored by Romantic-era composers for lyrical passages. Pop ballads, film scores, and neo-soul tracks often use Ab chords for their warm, enveloping quality — the key sits comfortably for many vocal ranges.
Common Progressions
The A♭ Sixth-Ninth Chord frequently appears in these progression patterns (shown in Roman numeral notation relative to key):
Songs Featuring the Sixth-Ninth Chord
Well-known songs where the A♭ Sixth-Ninth Chord — or this chord type — plays a prominent role:
- Chameleon – Herbie Hancock
- Mercy Mercy Mercy – Cannonball Adderley
- Four – Miles Davis
Tuning Frequencies Across Temperaments
Frequencies shown at A=440 Hz. View full temperament data for any note.
| Note | Equal Temp. | Pythagorean | Just Intonation |
|---|---|---|---|
| A♭4 | 415.305 Hz | 417.657 Hz | 418.601 Hz |
| C4 | 261.626 Hz | 260.740 Hz | 261.626 Hz |
| E♭4 | 311.127 Hz | 309.026 Hz | 313.951 Hz |
| F4 | 349.228 Hz | 347.654 Hz | 348.834 Hz |
| B♭4 | 466.164 Hz | 463.538 Hz | 470.926 Hz |
Scales Containing the A♭ Sixth-Ninth Chord
These scales include the A♭ Sixth-Ninth Chord as a diatonic or characteristic chord: