Bb
C#
D#
Bb
F#
A
E
C
G
D#
Bb
C
C#
E
F#
C#
A
C
G
D#
Bb
F#
C#
D#
E
G
A
E
C
D#
Bb
F#
C#
A
E
F#
G
Bb
C
G
D#
F#
C#
A
E
C
G
A
Bb
C#
D#
Bb
F#
A
E
C
G
D#
Bb
C
C#
E
F#
C#
A
C
G
D#
Bb
F#
C#
D#
E
G
A
E
C
D#
Bb
F#
C#
A
E
F#
G
Bb
C
G
D#
F#
C#
A
E
C
G
A
Bb
C#
D#
Bb
F#
A
E
C
G
D#
Bb
C
C#
E
F#
C#
A Half-Whole Diminished Scale notes: A Bb C C# D# E F# G. Formula: 1 b2 b3 3 #4 5 6 b7. Chords that fit it: A, Am, A7, Am7, Adim, Adim7, Am7b5, A5.
The half-whole diminished scale alternates half and whole steps: 1 b2 b3 3 #4 5 6 b7. It fits dominant chords with b9 and #9, so it is a jazz and fusion staple over 7b9 chords. It is symmetric: the pattern repeats every three frets, so there are only three different ones.