C altered scale on guitar

C altered uses C, D♭, E♭, F♭, G♭, A♭, B♭. Its Box 1 shape places the root on string 5, fret 3 for easy access to the ♭5.

F♭G♭B♭CE♭F♭A♭B♭CD♭F♭G♭EADGBE123
Positions on the neck1 of 6

How it is built

C1D♭♭2E♭♭3F♭♭4G♭♭5A♭♭6B♭♭7

Formula 1, ♭2, ♭3, ♭4, ♭5, ♭6, ♭7

How do you play the C altered scale on guitar?

C altered in box 1 runs from fret 0 to fret 3, 12 notes across 6 strings, from F♭ on the low E string at fret 0 up to G♭ on the high e string at fret 2. The root falls on the A string at fret 3 and the B string at fret 1.

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

Box 2 · frets 25

C altered in box 2 runs from fret 2 to fret 5, 13 notes across 6 strings, from G♭ on the low E string at fret 2 up to A♭ on the high e string at fret 4. The root falls on the A string at fret 3 and the G string at fret 5.

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

Box 3 · frets 47

C altered in box 3 runs from fret 4 to fret 7, 14 notes across 6 strings, from A♭ on the low E string at fret 4 up to B♭ on the high e string at fret 6. The root falls on the G string at fret 5.

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

Box 4 · frets 69

C altered in box 4 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 low E string at fret 8 and the high e string at fret 8.

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

Box 5 · frets 811

C altered in box 5 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 low E string at fret 8, the D string at fret 10 and the high e string at fret 8.

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

Box 6 · frets 1114

C altered in box 6 runs from fret 11 to fret 14, 16 notes across 6 strings, from E♭ on the low E string at fret 11 up to G♭ on the high e string at fret 14. The root falls on the B string at fret 13.

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

Why it sounds like that

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

When to use it

Use C altered over C7♭5 or C7♯5 chords in jazz, fusion, and bebop. It fits dominant chords that resolve to F minor or F major. The altered fifths and ninths add tension before a ii–V–I in F. Try it over C 7th flat 5 or C 7th sharp 5.

Which position to practise

Practise Box 1 first. It keeps the root on string 5, fret 3 and covers frets 0–3, making the half-step from C to D♭ easy to hear and finger.

Common questions

What notes are in C altered?

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

Which chords does C altered fit?

C altered fits dominant chords with altered fifths, such as C7♭5 and C7♯5. It also works over C7♭9 and C7♯9. These chords typically resolve to F minor or F major.

How does C altered differ from C locrian?

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

What is the step pattern for C altered?

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