B♭ acoustic scale on bass guitar

B♭ acoustic contains B♭, C, D, E, F, G, A♭. Box 2 keeps the root on string 4, fret 6 for a mid-neck run.

EFGB♭CDEFGA♭B♭EADG123
Positions on the neck1 of 5

How it is built

B♭1C2D3E♯4F5G6A♭♭7

Formula 1, 2, 3, ♯4, 5, 6, ♭7

How do you play the B♭ acoustic scale on bass?

B♭ acoustic in box 1 runs from fret 0 to fret 3, 11 notes across 4 strings, from E on the E string at fret 0 up to B♭ on the G string at fret 3. The root falls on the A string at fret 1 and the G string at fret 3.

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

Box 2 · frets 36

B♭ acoustic in box 2 runs from fret 3 to fret 6, 10 notes across 4 strings, from G on the E string at fret 3 up to C on the G string at fret 5. The root falls on the E string at fret 6 and the G string at fret 3.

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

Box 3 · frets 69

B♭ acoustic in box 3 runs from fret 6 to fret 9, 8 notes across 4 strings, from B♭ on the E string at fret 6 up to E on the G string at fret 9. The root falls on the E string at fret 6 and the D string at fret 8.

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

Box 4 · frets 811

B♭ acoustic in box 4 runs from fret 8 to fret 11, 9 notes across 4 strings, from C on the E string at fret 8 up to F on the G string at fret 10. The root falls on the D string at fret 8.

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

Box 5 · frets 1013

B♭ acoustic in box 5 runs from fret 10 to fret 13, 11 notes across 4 strings, from D on the E string at fret 10 up to A♭ on the G string at fret 13. The root falls on the A string at fret 13.

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

Why it sounds like that

B♭ acoustic is the fourth mode of F melodic minor, built 1, 2, 3, ♯4, 5, 6, ♭7. The ♯4 creates a tritone against the root, and the ♭7 removes the leading tone. Compare it to B♭ mixolydian, which lowers the ♯4 to a perfect 4th.

When to use it

B♭ acoustic fits B♭ major and B♭ 5th chords, and works over B♭7 in jazz-blues. The ♯4 adds a Lydian colour over dominant chords; resolve it to the 5th for a smooth line. Use it for fusion or modal rock in B♭.

Which position to practise

Learn Box 2 first: the root sits on string 4, fret 6, covering frets 3–6. It places the ♯4 on string 3 for easy hammer-ons.

Common questions

What notes are in B♭ acoustic?

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

Which chords does B♭ acoustic fit?

B♭ acoustic fits B♭ major and B♭ 5th chords. It also works over B♭7 in dominant contexts.

Is B♭ acoustic the same as B♭ mixolydian?

No. B♭ acoustic has a ♯4 (E), while B♭ mixolydian has a perfect 4th (E♭). The other six notes are identical.