C# Half-Whole Diminished Scale

C# Half-Whole Diminished Scale notes: C# D E E# F## G# A# B. Formula: 1 b2 b3 3 #4 5 6 b7. Chords that fit it: C#, C#m, C#7, C#m7, C#dim, C#dim7, C#m7b5, C#5.

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.