A altered scale on guitar

A altered uses A, B♭, C, D♭, E♭, F, G. Its half-step start makes Box 1 a compact way to target altered fifths.

FGB♭CD♭E♭FAB♭CD♭E♭FGEADGBE1234
Positions on the neck1 of 5

How it is built

A1B♭♭2C♭3D♭♭4E♭♭5F♭6G♭7

Formula 1, ♭2, ♭3, ♭4, ♭5, ♭6, ♭7

How do you play the A altered scale on guitar?

A altered in box 1 runs from fret 1 to fret 4, 14 notes across 6 strings, from F on the low E string at fret 1 up to G on the high e string at fret 3. The root falls on the G string at fret 2.

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

Box 2 · frets 36

A altered in box 2 runs from fret 3 to fret 6, 16 notes across 6 strings, from G on the low E string at fret 3 up to B♭ on the high e string at fret 6. The root falls on the low E string at fret 5 and the high e string at fret 5.

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

Box 3 · frets 58

A 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 low E string at fret 5, the D string at fret 7 and the high e string at fret 5.

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

Box 4 · frets 811

A altered in box 4 runs from fret 8 to fret 11, 16 notes across 6 strings, from C on the low E string at fret 8 up to E♭ on the high e string at fret 11. The root falls on the B string at fret 10.

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

Box 5 · frets 1114

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

Every note in this box, string by string
StringFretsNotes
6 (E)11, 13E♭, F
5 (A)12, 13A, B♭
4 (D)11, 13D♭, E♭
3 (G)12, 14G, A
2 (B)11, 13, 14B♭, C, D♭
1 (e)11, 13E♭, F

Why it sounds like that

A altered is the seventh mode of B♭ melodic minor. It lowers every scale degree except the root, giving 1, ♭2, ♭3, ♭4, ♭5, ♭6, ♭7. Compared with A locrian, the fourth is flattened from D to D♭. The half-whole pattern H, W, H, W, W, W, W creates a dense, tense sound.

When to use it

Use A altered over A7♭5 or A7♯5 chords in jazz, fusion, and bebop. It fits dominant chords that resolve to D minor or D major. The altered fifths and ninths add tension before a ii–V–I in D. Try it over A 7th flat 5 or A 7th sharp 5.

Which position to practise

Practise Box 1 first. It keeps the root on string 6, fret 5 and covers frets 1–4, making the half-step from A to B♭ easy to hear and finger.

Common questions

What notes are in A altered?

A altered contains A, B♭, C, D♭, E♭, F, and G. The formula is 1, ♭2, ♭3, ♭4, ♭5, ♭6, ♭7. It is the seventh mode of B♭ melodic minor.

Which chords does A altered fit?

A altered fits dominant chords with altered fifths, such as A7♭5 and A7♯5. It also works over A7♭9 and A7♯9. These chords typically resolve to D minor or D major.

How does A altered differ from A locrian?

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

What is the step pattern for A altered?

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