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F♯ 7th flat 5 chord on bass (F♯7♭5)
Also called or written F♯7♭5, F♯, F♯ Dominant 7th Flat 5 or F♯ 7th ♭5
F♯ 7th flat 5 contains F♯, A♯, C and E. The 2nd-fret shape is low on the neck, where the frets are wider and the stretch is more demanding.
How it is built
Formula 1, 3, ♭5, ♭7
How do you play an F♯ 7th flat 5 chord on bass?
F♯ 7th flat 5 is played at the 2nd fret as 2 3 2 3: index finger on the E string at fret 2, ring finger on the A string at fret 3, middle finger on the D string at fret 2 and pinky finger on the G string at fret 3.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 2 | 1 | F♯ (1) |
| 3 (A) | 3 | 3 | C (♭5) |
| 2 (D) | 2 | 2 | E (♭7) |
| 1 (G) | 3 | 4 | A♯ (3) |
AdvancedThe 2nd-fret shape requires the pinky to reach fret 3 on the 1st string while the index holds fret 2 on the 4th string, stretching the left hand.
14th fret
F♯ 7th flat 5 is played at the 14th fret as 14 15 14 15: index finger on the E string at fret 14, ring finger on the A string at fret 15, middle finger on the D string at fret 14 and pinky finger on the G string at fret 15.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 14 | 1 | F♯ (1) |
| 3 (A) | 15 | 3 | C (♭5) |
| 2 (D) | 14 | 2 | E (♭7) |
| 1 (G) | 15 | 4 | A♯ (3) |
F♯7♭5/C inversion
F♯ 7th flat 5 is played at the 8th fret as 8 9 8 9: index finger on the E string at fret 8, ring finger on the A string at fret 9, middle finger on the D string at fret 8 and pinky finger on the G string at fret 9.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 8 | 1 | C (♭5) |
| 3 (A) | 9 | 3 | F♯ (1) |
| 2 (D) | 8 | 2 | A♯ (3) |
| 1 (G) | 9 | 4 | E (♭7) |
Why it sounds like that
F♯ 7th flat 5 is built from the formula 1, 3, ♭5, ♭7. The diminished 5th between F♯ and C defines its unstable quality. Compare it with F♯ 7th, which has a perfect 5th.
What goes wrong with F♯ 7th flat 5?
- Letting the pinky collapse on the 1st string, which mutes the E at fret 3.
- Pressing the ring finger too flat on the 3rd string, so it deadens the 2nd string next to it.
- Striking the open 5th string, which is not part of the chord and adds an unwanted F♯.
When to use it
F♯ 7th flat 5 functions as a dominant chord in B minor or as a passing chord in jazz. It can substitute for F♯ 7th when the ♭5 is needed. Its tense sound fits bebop and fusion lines.
Changing to and from F♯ 7th flat 5
- Move to F 7th flat 5 by sliding the shape down one fret to the 1st fret.
- Move to G 7th flat 5 by sliding the shape up one fret to the 3rd fret.
Which voicing to use
The 2nd-fret shape keeps F♯ in the bass for a root-position sound. The F♯7♭5/C inversion at fret 8 puts the ♭5 in the bass, creating a darker, less stable feel.
Other F♯ chords
Common questions
How is F♯ 7th flat 5 written?
F♯ 7th flat 5 is written F♯7♭5 or F#7♭5. The symbol F♯ is also used, and the chord is sometimes called Dominant 7th Flat 5. It is also spelled G♭ in enharmonic notation for the same sounding root.
What is the difference between F♯7♭5 and F♯7?
F♯7♭5 has a diminished 5th (C) instead of the perfect 5th (C♯) in F♯7. That one note changes the chord from bluesy to tense and unresolved.
Can F♯7♭5 be used in place of F♯7?
F♯7♭5 can replace F♯7 when the melody or solo uses the ♭5. In a standard blues, the ♭5 may clash with the expected perfect 5th, so use it selectively.