G altered scale on guitar

G altered uses G, A♭, B♭, C♭, D♭, E♭, F. Its Box 1 shape places the root on string 6, fret 3 for a low altered run.

FGA♭B♭C♭D♭E♭FA♭B♭C♭D♭E♭FGA♭EADGBE1234
Positions on the neck1 of 5

How it is built

G1A♭♭2B♭♭3C♭♭4D♭♭5E♭♭6F♭7

Formula 1, ♭2, ♭3, ♭4, ♭5, ♭6, ♭7

How do you play the G altered scale on guitar?

G altered in box 1 runs from fret 1 to fret 4, 16 notes across 6 strings, from F on the low E string at fret 1 up to A♭ on the high e string at fret 4. The root falls on the low E string at fret 3 and the high e string at fret 3.

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

Box 2 · frets 36

G 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 3, the D string at fret 5 and the high e string at fret 3.

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

Box 3 · frets 69

G altered in box 3 runs from fret 6 to fret 9, 16 notes across 6 strings, from B♭ on the low E string at fret 6 up to D♭ on the high e string at fret 9. The root falls on the B string at fret 8.

Every note in this box, string by string
StringFretsNotes
6 (E)6, 7, 9B♭, C♭, D♭
5 (A)6, 8E♭, F
4 (D)6, 8, 9A♭, B♭, C♭
3 (G)6, 8D♭, E♭
2 (B)6, 8, 9F, G, A♭
1 (e)6, 7, 9B♭, C♭, D♭

Box 4 · frets 912

G altered in box 4 runs from fret 9 to fret 12, 13 notes across 6 strings, from D♭ on the low E string at fret 9 up to E♭ on the high e string at fret 11. The root falls on the A string at fret 10 and the G string at fret 12.

Every note in this box, string by string
StringFretsNotes
6 (E)9, 11D♭, E♭
5 (A)10, 11G, A♭
4 (D)9, 11C♭, D♭
3 (G)10, 12F, G
2 (B)9, 11, 12A♭, B♭, C♭
1 (e)9, 11D♭, E♭

Box 5 · frets 1114

G altered in box 5 runs from fret 11 to fret 14, 14 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 G string at fret 12.

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

Why it sounds like that

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

When to use it

Use G altered over G7♭5 or G7♯5 chords in jazz, fusion, and bebop. It fits dominant chords that resolve to C minor or C major. The altered fifths and ninths add tension before a ii–V–I in C. Try it over G 7th flat 5 or G 7th sharp 5.

Which position to practise

Practise Box 1 first. It keeps the root on string 6, fret 3 and covers frets 1–4, making the half-step from G to A♭ easy to hear and finger.

Common questions

What notes are in G altered?

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

Which chords does G altered fit?

G altered fits dominant chords with altered fifths, such as G7♭5 and G7♯5. It also works over G7♭9 and G7♯9. These chords typically resolve to C minor or C major.

How does G altered differ from G locrian?

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

What is the step pattern for G altered?

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