"Blue Powder" has a lot going on Chord-Scale-wise. Has anyone analyzed it?
I'm working on my analysis as we speak.

So far I've found that Vai uses Aeolian, Dorian, Lydian, Mixolydian, Phrygian Dominant, Lydian Augmented, & maybe Diminished.
I charted out the progression & started assigning chord-scales to each chord.
Knowing all of this helps you understand not only the note choices in the solo/melody but also the chord voicings in the accompaniment. It also gives you a deeper understanding of Vai's compositional technique.

Hey man,

It is good to learn CST (Chord scale theory) especially for jazz. However I just want to give a bit of a warning to diving too deep into that stuff with rock. A lot of what Steve Vai does is what sounds good. Keep on learning chord theory, but transcribe a lot and work on ear training as well.