Watch the Up a Flat 3rd: Alt. Dom. II-V-I online guitar lesson by Kenny Wessel from Shades of Jazz
I'm playing over a II-V7alt-I 4-bar vamp in this section and using the minor pentatonic scale a flat third up from the root of the dominant seventh chord to get an altered sounding scale. The progression is C-7 / F7#9b13 / Bbmaj7. I can use a C minor pentatonic scale for the C-7, an Ab minor pentatonic mode over the F7alt, and resolve to an A blues scale to get a Lydian sound over the Bbmaj7.