B♭ blues diminished scale on bass guitar

B♭ blues diminished runs B♭, C♭, D♭, D, F♭, F, G, A♭. Practise Box 2 to keep the root on string 4, fret 6.

F♭FGB♭C♭DF♭FGA♭B♭EADG123
Positions on the neck1 of 4

How it is built

B♭1C♭♭2D♭♭3D3F♭♭5F5G6A♭♭7

Formula 1, ♭2, ♭3, 3, ♭5, 5, 6, ♭7

How do you play the B♭ blues diminished scale on bass?

B♭ blues diminished in box 1 runs from fret 0 to fret 3, 11 notes across 4 strings, from F♭ 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, 3F♭, F, G
3 (A)1, 2B♭, C♭
2 (D)0, 2, 3D, F♭, F
1 (G)0, 1, 3G, A♭, B♭

Box 2 · frets 36

B♭ blues diminished 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 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)4, 5D♭, D
2 (D)3, 5, 6F, G, A♭
1 (G)3, 4, 6B♭, C♭, D♭

Box 3 · frets 69

B♭ blues diminished in box 3 runs from fret 6 to fret 9, 11 notes across 4 strings, from B♭ on the E string at fret 6 up to F♭ 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, 7, 9B♭, C♭, D♭
3 (A)7, 8F♭, F
2 (D)6, 8, 9A♭, B♭, C♭
1 (G)6, 7, 9D♭, D, F♭

Box 4 · frets 912

B♭ blues diminished in box 4 runs from fret 9 to fret 12, 11 notes across 4 strings, from D♭ on the E string at fret 9 up to G on the G string at fret 12. No root falls inside this box; it sits between two of them.

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

Why it sounds like that

B♭ blues diminished adds a ♭2 to the B♭ hungarian major scale, which supplies the other seven notes. The scale contains a tritone between B♭ and F♭, but no leading tone. Compare it with B♭ hungarian major.

When to use it

B♭ blues diminished fits B♭ major and B♭ minor chords for blues lines. It also works over B diminished and B diminished 7th in passing. Use it in B♭ blues progressions when you need a darker, chromatic edge.

Which position to practise

Learn Box 2 first: it keeps the B♭ root on string 4, fret 6 and string 1, fret 3. That position covers frets 3–6 and sets up Box 3.

Common questions

What notes are in B♭ blues diminished?

B♭ blues diminished contains B♭, C♭, D♭, D, F♭, F, G, and A♭. The scale degrees are 1, ♭2, ♭3, 3, ♭5, 5, 6, and ♭7. It has eight notes total. It is also spelled A♯ in enharmonic notation for the same sounding root.

What chords does B♭ blues diminished fit?

B♭ blues diminished fits B♭ major and B♭ minor chords. It also works over B diminished and B diminished 7th chords. Use it for blues lines with a chromatic twist.

What is the difference between B♭ blues diminished and B♭ hungarian major?

B♭ blues diminished adds a ♭2 to B♭ hungarian major. B♭ hungarian major has seven notes: B♭, D♭, D, F♭, F, G, A♭. The blues diminished version includes C♭ as the extra note.

Does B♭ blues diminished contain a tritone?

B♭ blues diminished contains a tritone between B♭ and F♭. That interval is a diminished fifth, six semitones above the root. It does not contain a leading tone.