A altered scale on bass guitar

A altered contains A, B♭, C, D♭, E♭, F, and G. Box 1 places the root on string 4, fret 5 for a compact altered-dominant shape.

FGB♭CD♭E♭FAB♭EADG1234
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 bass?

A altered in box 1 runs from fret 1 to fret 4, 9 notes across 4 strings, from F on the E string at fret 1 up to B♭ on the G string at fret 3. The root falls on the G string at fret 2.

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

Box 2 · frets 36

A altered in box 2 runs from fret 3 to fret 6, 11 notes across 4 strings, from G on the E string at fret 3 up to D♭ on the G string at fret 6. The root falls on the E string at fret 5.

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

Box 3 · frets 58

A altered in box 3 runs from fret 5 to fret 8, 11 notes across 4 strings, from A on the E string at fret 5 up to E♭ on the G string at fret 8. The root falls on the E string at fret 5 and the D string at fret 7.

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

Box 4 · frets 811

A altered in box 4 runs from fret 8 to fret 11, 10 notes across 4 strings, from C on the E string at fret 8 up to F on the G string at fret 10. No root falls inside this box; it sits between two of them.

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

Box 5 · frets 1114

A altered in box 5 runs from fret 11 to fret 14, 8 notes across 4 strings, from E♭ on the E string at fret 11 up to A on the G string at fret 14. 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
4 (E)11, 13E♭, F
3 (A)12, 13A, B♭
2 (D)11, 13D♭, E♭
1 (G)12, 14G, A

Why it sounds like that

A altered lowers the fourth of A locrian to D♭, creating a 1, ♭2, ♭3, ♭4, ♭5, ♭6, ♭7 set. The scale contains a tritone between A and E♭. Compare it with A locrian to hear the ♭4 change.

When to use it

A altered fits A 7th flat 5 and A 7th sharp 5 chords. Use it over A 7th flat 5 in jazz or fusion lines. The ♭2 and ♭6 add tension to dominant resolutions.

Which position to practise

Practise Box 1 first. The root sits on string 4, fret 5, keeping the hand in one position for the full scale.

Common questions

What notes are in A altered?

A altered contains A, B♭, C, D♭, E♭, F, and G. The scale degrees are 1, ♭2, ♭3, ♭4, ♭5, ♭6, ♭7. It is also called Altered Dominant.

Which chords does A altered fit?

A altered fits A 7th flat 5 and A 7th sharp 5 chords. The scale works over dominant chords with altered fifths. Use it for jazz or fusion lines.

How does A altered differ from A locrian?

A altered lowers the fourth degree from D to D♭. This creates a ♭4 interval instead of a perfect fourth. The rest of the scale matches A locrian.