F# Sixth-Ninth Chord
Chord Tones: F# Sixth-Ninth Chord
Symbol: 6/9 — Formula: 1-3-5-6-9
| Degree | Note | Frequency (A=440, Equal) |
|---|---|---|
| 1 | F# | 369.994 Hz |
| 3 | A# | 466.164 Hz |
| 5 | C# | 277.183 Hz |
| 6 | D# | 311.127 Hz |
| 9 | G# | 415.305 Hz |
Chord Notation
| Notation Type | Symbol / Value |
|---|---|
| Lead Sheet Symbol | F#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 | F# – A# – C# – D# – G# | F# | F# Sixth-Ninth Chord |
| First Inversion | A# – C# – D# – G# – F# | A# | F# Sixth-Ninth Chord/A# |
| Second Inversion | C# – D# – G# – F# – A# | C# | F# Sixth-Ninth Chord/C# |
| Third Inversion | D# – G# – F# – A# – C# | D# | F# Sixth-Ninth Chord/D# |
| Fourth Inversion | G# – F# – A# – C# – D# | G# | F# Sixth-Ninth Chord/G# |
Harmonic Function
The F# sixth ninth chord commonly functions as the tritone substitution in C major or tonic in F# 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 F# 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 F# 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 |
|---|---|---|---|
| F# | 369.994 Hz | 371.251 Hz | 367.911 Hz |
| A# | 466.164 Hz | 463.538 Hz | 470.926 Hz |
| C# | 277.183 Hz | 278.437 Hz | 279.067 Hz |
| D# | 311.127 Hz | 309.026 Hz | 313.951 Hz |
| G# | 415.305 Hz | 417.657 Hz | 418.601 Hz |
Scales Containing the F# Sixth-Ninth Chord
These scales include the F# Sixth-Ninth Chord as a diatonic or characteristic chord: