Can also function as an Ab altered dominant, giving these alterations: #5 and #9 This gives the formular of substituting a lydian #9 chord a major third away from the root of an altered dominant.
C² Can be approached by 4 different dominant chords, each a minor third apart.
13
13th arpeggios Bb7
16
G7 Bb7 Db7 E7
We can apply the substitution to each of these chords, giving us 4 different Lydian #9 scales.
D Lydian #9
Diatonic triads from two scales. D Lydian #9 F Lydian #9
B Lydian #9 D Lydian #9 F Lydian #9 Ab Lydian #9
C²
Db7
C²
Although the scale is functioning in the context of the altered dominant it is substituting for, on another level, it is also functioning in it's own right. This is a tonic with a raised ninth; thus it can also be approached by one of it's own dominant chords, as detailed above.
