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B♭ altered dominant double b3 Scale — Guitar Fretboard Visualization

Low E string: Fb, Gb, Ab, Bb, Cb, Dbb, Ebb, Fb at frets 0, 2, 4, 6, 7, 8, 10, 12

A string: Bb, Cb, Dbb, Ebb, Fb, Gb, Ab at frets 1, 2, 3, 5, 7, 9, 11

D string: Ebb, Fb, Gb, Ab, Bb, Cb, Dbb, Ebb at frets 0, 2, 4, 6, 8, 9, 10, 12

G string: Ab, Bb, Cb, Dbb, Ebb, Fb, Gb at frets 1, 3, 4, 5, 7, 9, 11

B string: Cb, Dbb, Ebb, Fb, Gb, Ab, Bb, Cb at frets 0, 1, 3, 5, 7, 9, 11, 12

High E string: Fb, Gb, Ab, Bb, Cb, Dbb, Ebb, Fb at frets 0, 2, 4, 6, 7, 8, 10, 12

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Bb altered dominant double b3

The altered dominant double b3 scale, the seventh mode of the neapolitan major scale, is the altered scale pushed one notch further: the sharp 9 is flattened again to a double-flat 3rd. Every degree from 2 to 7 is lowered, some twice. It is about as much tension as seven notes can carry, for altered dominants at the outer edge of jazz harmony.

it consists of these notes and degrees:

B♭

I

D𝄫7no5/Bb
C♭

bii

C♭m
D𝄫

bbIII+

D𝄫aug
E𝄫

bIV+

E𝄫aug
F♭

bV

F♭maj
G♭

bVI

G♭majb5
A♭

bvii°

A♭dim

Same notes, different mode

Bb altered dominant double b3 uses the same notes as the scales below. Start from a different note and you get a new mode built on the very same note set.

Cb neapolitan majorC leading whole toneD lydian augmented dominantFb lydian dominant b6Gb major locrianAb half-diminished b4

altered dominant double b3 in all 12 keys, with chords and related scales

tip
  • Every degree above the root is lowered, some twice: use Bb altered dominant double b3 (Db) for one bar of maximum dominant tension, then resolve.
  • The double-flat 3rd (C) is enharmonically the 9th of the chord a half step down; voice-lead it there and the wildness turns logical.
  • Anchor on the tritone between the root and b5 (E); it is the only interval here the ear can hold onto.
  • As the seventh mode of neapolitan major, it shares its pitch set with the neapolitan major a half step above Bb.

How to play B♭ altered dominant double b3 on guitar

A-shape barre falls on fret 1, which means this key voices from about the lowest position going. Clamp a capo there and the shapes read as A fingering, so 7 flats stay off your left hand. Open B sounds the minor second while the E pair covers the diminished fifth, so open pedals sit under fretted lines. Another root waits three frets up the G string. Fret 10 marks where the first box ends.

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