F♯ altered scale on guitar

F♯ altered uses F♯, G, A, B♭, C, D, E. Its Box 1 shape places the root on string 6, fret 2 for a low altered run.

EF♯GAB♭CDEGAB♭CDEF♯GEADGBE123
Positions on the neck1 of 5

How it is built

F♯1G♭2A♭3B♭♭4C♭5D♭6E♭7

Formula 1, ♭2, ♭3, ♭4, ♭5, ♭6, ♭7

How do you play the F♯ altered scale on guitar?

F♯ altered in box 1 runs from fret 0 to fret 3, 16 notes across 6 strings, from E on the low E string at fret 0 up to G on the high e string at fret 3. The root falls on the low E string at fret 2 and the high e string at fret 2.

Every note in this box, string by string
StringFretsNotes
6 (E)0, 2, 3E, F♯, G
5 (A)0, 1, 3A, B♭, C
4 (D)0, 2D, E
3 (G)0, 2, 3G, A, B♭
2 (B)1, 3C, D
1 (e)0, 2, 3E, F♯, G

Box 2 · frets 25

F♯ altered in box 2 runs from fret 2 to fret 5, 16 notes across 6 strings, from F♯ on the low E string at fret 2 up to A on the high e string at fret 5. The root falls on the low E string at fret 2, the D string at fret 4 and the high e string at fret 2.

Every note in this box, string by string
StringFretsNotes
6 (E)2, 3, 5F♯, G, A
5 (A)3, 5C, D
4 (D)2, 4, 5E, F♯, G
3 (G)2, 3, 5A, B♭, C
2 (B)3, 5D, E
1 (e)2, 3, 5F♯, G, A

Box 3 · frets 58

F♯ altered in box 3 runs from fret 5 to fret 8, 16 notes across 6 strings, from A on the low E string at fret 5 up to C on the high e string at fret 8. The root falls on the B string at fret 7.

Every note in this box, string by string
StringFretsNotes
6 (E)5, 6, 8A, B♭, C
5 (A)5, 7D, E
4 (D)5, 7, 8G, A, B♭
3 (G)5, 7C, D
2 (B)5, 7, 8E, F♯, G
1 (e)5, 6, 8A, B♭, C

Box 4 · frets 811

F♯ altered in box 4 runs from fret 8 to fret 11, 13 notes across 6 strings, from C on the low E string at fret 8 up to D on the high e string at fret 10. The root falls on the A string at fret 9 and the G string at fret 11.

Every note in this box, string by string
StringFretsNotes
6 (E)8, 10C, D
5 (A)9, 10F♯, G
4 (D)8, 10B♭, C
3 (G)9, 11E, F♯
2 (B)8, 10, 11G, A, B♭
1 (e)8, 10C, D

Box 5 · frets 1013

F♯ altered in box 5 runs from fret 10 to fret 13, 14 notes across 6 strings, from D on the low E string at fret 10 up to E on the high e string at fret 12. The root falls on the G string at fret 11.

Every note in this box, string by string
StringFretsNotes
6 (E)10, 12D, E
5 (A)10, 12, 13G, A, B♭
4 (D)10, 12C, D
3 (G)11, 12F♯, G
2 (B)10, 11, 13A, B♭, C
1 (e)10, 12D, E

Why it sounds like that

F♯ altered is the seventh mode of G melodic minor. The scale spells 1, ♭2, ♭3, ♭4, ♭5, ♭6, ♭7, with B♭ as the ♭4 and C as the ♭5. Compared with F♯ locrian, the fourth drops from B to B♭. The pattern H, W, H, W, W, W, W keeps half steps at the start and middle.

When to use it

Use F♯ altered over F♯7♭5 or F♯7♯5 chords in jazz, fusion, and bebop. It fits dominant chords that resolve to B minor or B major. The altered fifths and ninths add tension before a ii–V–I in B. Try it over F♯ 7th flat 5 or F♯ 7th sharp 5.

Which position to practise

Practise Box 1 first. It keeps the root on string 6, fret 2 and covers frets 0–3, making the half-step from F♯ to G easy to hear and finger.

Common questions

What notes are in F♯ altered?

F♯ altered contains F♯, G, A, B♭, C, D, and E. The formula is 1, ♭2, ♭3, ♭4, ♭5, ♭6, ♭7. It is the seventh mode of G melodic minor. It is also spelled G♭ in enharmonic notation for the same sounding root.

Which chords does F♯ altered fit?

F♯ altered fits dominant chords with altered fifths, such as F♯7♭5 and F♯7♯5. It also works over F♯7♭9 and F♯7♯9. These chords typically resolve to B minor or B major.

How does F♯ altered differ from F♯ locrian?

F♯ altered has a flattened fourth (B♭) while F♯ locrian has a perfect fourth (B). The rest of the notes are identical. This single change makes altered sound more dissonant.

What is the step pattern for F♯ altered?

The step pattern is H, W, H, W, W, W, W. Starting on F♯, that gives F♯–G–A–B♭–C–D–E. The half steps fall between the first two and third and fourth degrees.