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F♯ augmented chord on bass (F♯aug)
Also called or written F♯aug or F♯+
F♯ augmented contains F♯, A♯, and C♯♯. The open voicing uses an open D string, making the chord easy to grab but slightly awkward to fret cleanly.
How it is built
Formula 1, 3, ♯5
How do you play an F♯ augmented chord on bass?
F♯ augmented is played in open position as 2 1 0 3: middle finger on the E string at fret 2, index finger on the A string at fret 1 and ring finger on the G string at fret 3. The D string rings open.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 2 | 2 | F♯ (1) |
| 3 (A) | 1 | 1 | A♯ (3) |
| 2 (D) | open | — | C♯♯ (♯5) |
| 1 (G) | 3 | 3 | A♯ (3) |
BeginnerThe open voicing requires fretting three strings while keeping the open D string clear, which can cause accidental muting.
7th fret
F♯ augmented is played at the 7th fret as × 9 8 7: ring finger on the A string at fret 9, middle finger on the D string at fret 8 and index finger on the G string at fret 7. The E string stays muted.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | muted | — | — |
| 3 (A) | 9 | 3 | F♯ (1) |
| 2 (D) | 8 | 2 | A♯ (3) |
| 1 (G) | 7 | 1 | C♯♯ (♯5) |
12th fret
F♯ augmented is played at the 12th fret as 14 13 12 ×: ring finger on the E string at fret 14, middle finger on the A string at fret 13 and index finger on the D string at fret 12. The G string stays muted.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 14 | 3 | F♯ (1) |
| 3 (A) | 13 | 2 | A♯ (3) |
| 2 (D) | 12 | 1 | C♯♯ (♯5) |
| 1 (G) | muted | — | — |
F♯aug/A♯ inversion · fret 4
F♯ augmented is played at the 4th fret as 6 5 4 ×: ring finger on the E string at fret 6, middle finger on the A string at fret 5 and index finger on the D string at fret 4. The G string stays muted.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 6 | 3 | A♯ (3) |
| 3 (A) | 5 | 2 | C♯♯ (♯5) |
| 2 (D) | 4 | 1 | F♯ (1) |
| 1 (G) | muted | — | — |
F♯aug/A♯ inversion · fret 11
F♯ augmented is played at the 11th fret as × 13 12 11: ring finger on the A string at fret 13, middle finger on the D string at fret 12 and index finger on the G string at fret 11. The E string stays muted.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | muted | — | — |
| 3 (A) | 13 | 3 | A♯ (3) |
| 2 (D) | 12 | 2 | C♯♯ (♯5) |
| 1 (G) | 11 | 1 | F♯ (1) |
Why it sounds like that
F♯ augmented is built from the 1, 3, ♯5 formula: F♯, A♯, and C♯♯. The augmented 5th, C♯♯, gives the chord its distinctive unstable sound. Compare it with F♯ major, which uses a perfect 5th instead.
What goes wrong with F♯ augmented?
- Letting the middle finger lean on the open D string, dulling the C♯♯.
- Fretting the E string too far from the fret, causing a buzz on F♯.
- Striking the A string too hard, making the A♯ overpower the chord.
When to use it
F♯ augmented fits as a passing chord in F♯ major progressions like F♯–B–C♯, the I–IV–V in F♯ major. Use it to add tension before resolving to F♯ major or F♯ 5th. It suits jazz, fusion, and dramatic rock.
Changing to and from F♯ augmented
- Sliding the shape down two frets to the 5th fret gives E augmented; keep the same finger pattern and move all fretted notes together.
Which voicing to use
The open position puts the root F♯ in the bass, giving a solid foundation. The 7th fret voicing raises the register for a brighter cut, while the F♯aug/B♭ inversion places A♯ in the bass for a less stable, more directional sound.
Other F♯ chords
Common questions
How is F♯ augmented written?
F♯ augmented is written as F♯+ or F♯aug. The ASCII root spelling is F#. It is also spelled G♭ in enharmonic notation for the same sounding root.
What is the difference between F♯ augmented and F♯ major?
F♯ augmented raises the 5th from C♯ to C♯♯, creating an augmented 5th interval. This gives the chord a tense, unresolved quality compared to F♯ major's stable perfect 5th.
Can F♯ augmented be used as a substitute for F♯ major?
F♯ augmented can substitute for F♯ major when you want a more dissonant sound. It works especially well in dominant contexts or as a passing chord.