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 | 440.000 Hz |
| 3 | C# | 277.183 Hz |
| 5 | E | 329.628 Hz |
| 6 | F# | 369.994 Hz |
| 9 | B | 493.883 Hz |
Chord Notation
| Notation Type | Symbol / Value |
|---|---|
| Lead Sheet Symbol | A6/9 |
| 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 – C# – E – F# – B | A | A Sixth-Ninth Chord |
| First Inversion | C# – E – F# – B – A | C# | A Sixth-Ninth Chord/C# |
| Second Inversion | E – F# – B – A – C# | E | A Sixth-Ninth Chord/E |
| Third Inversion | F# – B – A – C# – E | F# | A Sixth-Ninth Chord/F# |
| Fourth Inversion | B – A – C# – E – F# | B | A Sixth-Ninth Chord/B |
Harmonic Function
The A sixth ninth chord commonly functions as the submediant (vi) in C major or dominant (V) in D 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.
Common Progressions
The A Sixth-Ninth Chord frequently appears in these progression patterns (shown in Roman numeral notation relative to key):
I6/9-IVmaj7
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 | 440.000 Hz | 440.000 Hz | 436.043 Hz |
| C# | 277.183 Hz | 278.437 Hz | 279.067 Hz |
| E | 329.628 Hz | 330.001 Hz | 327.032 Hz |
| F# | 369.994 Hz | 371.251 Hz | 367.911 Hz |
| B | 493.883 Hz | 495.000 Hz | 490.548 Hz |
Scales Containing the A Sixth-Ninth Chord
These scales include the A Sixth-Ninth Chord as a diatonic or characteristic chord: