I'm looking at the song "Edward Lee" by Harold Mabern, Jr. (as it's presented in The Real Easy Book in C) and I'm trying to understand how to apply scales approach to soloing over its chords. There are two chords that appear problematic.
The chord progression for part A is
| Em7 | % | % | A7 | | B7 | Em7 | Cmaj7 | B7 Em7 |
For part B:
| G7 | Cmaj7 | E7 | Amaj7 | | D7 | Gmaj7 | C7sus | B7 |
The supplemental material page for this song suggests that all the major dominant chords in the song correspond to Mixolydian mode. However,
E7 chords have
G natural and
C natural respectively in the melody over them, which are 6♭ and aren't in the Mixolydian scale.
So the question is: is simply adding the 6♭ to the Mixolydian scale for these two chords a reasonable approach here? I'm also interested why the 6♭ notes really seem to work well with the harmony in this song.