The standard grips this chord is usually shown with.
F#aug9 is F#, A#, D, E and G# — F#7 with the fifth raised and the natural ninth added on top.
It sounds bright, tense and slightly unreal. Raising the fifth leaves no semitone in the lower half of the chord, which is where the whole-tone flavour comes from.

| F# | A# | D | E | G# |
|---|---|---|---|---|
| 1 | 3 | ♯5 | ♭7 | 9 |
Altered dominant — dominant pull with a whole-tone colour.
Also written F#9#5, F#+9 or F#9(#5). The same chord either way; which spelling you meet depends on who wrote the chart.
F#aug9 in 3rd inversion puts E in the bass instead of F#, the 7th of the chord. The notes are the same; what changes is what the bass line does, which is most of why you would reach for it — it lets the lowest voice move by step where the root would have jumped.
2 of F#aug9’s 9 common shapes do this: xx2334, 12-11-12-11-11-12.
Start with xx2334 — no barre and down at the nut. 1 of the 9 shapes here sits in open position. 3 of the 9 need a barre. Together they cover the neck from the 1st fret to the 15th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| 212130 | open position | F#, root position | E | 1 open string |
| 2x2334 | 2nd fret | F#, root position | G# | all fretted |
| xx2334 | 2nd fret | E, 3rd inversion | G# | all fretted |
| 676776 | 6th fret | A#, 1st inversion | A# | barred |
| x98790 | 7th fret | F#, root position | G# | 1 open string |
| x-9-8-9-9-10 | 8th fret | F#, root position | D | barred |
| 14-x-12-13-11-0 | 11th fret | F#, root position | A# | 1 open string |
| 12-11-12-11-11-12 | 11th fret | E, 3rd inversion | E | barred |
| 14-13-14-13-15-x | 13th fret | F#, root position | D | all fretted |
The same notes rebuilt from scratch give 7 shell and 14 rootless voicings, each on its own page.
Tensions. A shell of F#aug9, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (B#).
F#aug9 is a dominant with its tension raised, so it still points at B — harder than a plain seventh does, because the altered tones sit a semitone from where they are going.
Voice by voice, F#aug9 → B. 3 voices move by a semitone, and one note is common to both chords.
| In F#aug9 | Moves | In B |
|---|---|---|
| F#, the root | stays where it is | F#, the fifth |
| A#, the major third | rises a semitone | B, the root |
| D, the sharp fifth | rises a semitone | D#, the major third |
| E, the flat seventh | falls a semitone | D#, the major third |
| G#, the ninth | falls a whole tone | F#, the fifth |
Every note of F#aug9 is in F# whole tone.
Change one note of F#aug9 and you have F#alt (the ninth becomes a flat ninth), F#aug7 (drop the ninth), F#9 (the sharp fifth becomes a fifth) or F#9b5 (the sharp fifth becomes a flat fifth).
F#aug9 is an altered chord — a dominant seventh with its fifth or ninth moved. Altered dominant chords on every root.
On F#aug9’s sound and use this page follows Mark Levine, The Jazz Theory Book (Sher Music, 1995). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.