STRINGSCALES

G half-diminished b4 Scale — Guitar Fretboard Visualization

Low E string: F, G, A, Bb, Cb, Db, Eb at frets 1, 3, 5, 6, 7, 9, 11

A string: A, Bb, Cb, Db, Eb, F, G, A at frets 0, 1, 2, 4, 6, 8, 10, 12

D string: Eb, F, G, A, Bb, Cb, Db at frets 1, 3, 5, 7, 8, 9, 11

G string: G, A, Bb, Cb, Db, Eb, F, G at frets 0, 2, 3, 4, 6, 8, 10, 12

B string: Cb, Db, Eb, F, G, A, Bb, Cb at frets 0, 2, 4, 6, 8, 10, 11, 12

High E string: F, G, A, Bb, Cb, Db, Eb at frets 1, 3, 5, 6, 7, 9, 11

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G half-diminished b4

The half-diminished b4 scale, the sixth mode of the neapolitan major scale, takes the locrian #2 half-diminished sound and lowers the 4th as well. With the 3rd and 4th collapsed together it is nearly a cluster scale, keeping only the natural 2nd as breathing room. A specialist color for m7b5 chords in dense modern jazz writing.

it consists of these notes and degrees:

G

i°

Gdim
A

II

C♭7no5/A
B♭

biii

B♭m
C♭

bIV+

C♭aug
D♭

bV+

D♭aug
E♭

bVI

E♭maj
F

bVII

Fmaj♭5

Same notes, different mode

G half-diminished b4 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.

A altered dominant double b3Bb neapolitan majorCb leading whole toneDb lydian augmented dominantEb lydian dominant b6F major locrian

half diminished b4 in all 12 keys, with chords and related scales

tip
  • Nearly a cluster: with bIII (Bb) and b4 (B) adjacent, arpeggiate root, b5 (Db), b7 (F) first and add the packed middle notes as passing color.
  • Over a m7b5 chord in dense modern-jazz writing, the b4 (B) acts as a blue third-below-the-third; resolve it down to bIII (Bb).
  • Keep the natural 2nd (A) as your breathing room; it is the only bright interval in the scale.
  • It is the sixth mode of neapolitan major: the parent fingering a major 3rd below G plays it directly.

How to play G half-diminished b4 on guitar

Open G supplies the root, open A a major second and open B the diminished fourth, so three open strings back a fretted line. Fret 3 carries roots on both E strings, which lets a barre and a line share one hand position. Tonic chord is Gdim and no degree acts as a functional dominant. A altered dominant double b3 needs no new fingering, so the shape works for two roots. Fret 7 closes position one.

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