STRINGSCALES

C half-diminished b4 Scale — Guitar Fretboard Visualization

Low E string: Fb, Gb, Ab, Bb, C, D, Eb, Fb at frets 0, 2, 4, 6, 8, 10, 11, 12

A string: Bb, C, D, Eb, Fb, Gb, Ab at frets 1, 3, 5, 6, 7, 9, 11

D string: D, Eb, Fb, Gb, Ab, Bb, C, D at frets 0, 1, 2, 4, 6, 8, 10, 12

G string: Ab, Bb, C, D, Eb, Fb, Gb at frets 1, 3, 5, 7, 8, 9, 11

B string: C, D, Eb, Fb, Gb, Ab, Bb at frets 1, 3, 4, 5, 7, 9, 11

High E string: Fb, Gb, Ab, Bb, C, D, Eb, Fb at frets 0, 2, 4, 6, 8, 10, 11, 12

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C 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:

C

i°

Cdim
D

II

F♭7no5/D
E♭

biii

E♭m
F♭

bIV+

F♭aug
G♭

bV+

G♭aug
A♭

bVI

A♭maj
B♭

bVII

B♭majb5

Same notes, different mode

C 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.

D altered dominant double b3Eb neapolitan majorFb leading whole toneGb lydian augmented dominantAb lydian dominant b6Bb major locrian

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

tip
  • Nearly a cluster: with bIII (Eb) and b4 (E) adjacent, arpeggiate root, b5 (Gb), b7 (Bb) first and add the packed middle notes as passing color.
  • Over a m7b5 chord in dense modern-jazz writing, the b4 (E) acts as a blue third-below-the-third; resolve it down to bIII (Eb).
  • Keep the natural 2nd (D) 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 C plays it directly.

How to play C half-diminished b4 on guitar

Scale tones cover open D plus the E pair, which lands on the diminished fourth, so a fretted line can lean on open strings. Tonic chord is Cdim and none of the seven degrees works as a functional dominant, which means resolution must come out of voice leading. B string root sits one fret from the nut. D altered dominant double b3 uses the identical fingering 2 semitones up, so one shape does double duty. Fret 12 begins the second position.

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