I take it the Lydian Scale is used over the maj7 chord because all 7 tones are resting areas. The #11 does not create tension like the natural 11. Now if we are in G major, and have a D7 chord aproaching the Gmaj, the flat 5 sub gives us A flat 7. In the purest sense, that is A flat Mixolydian. I alwyas group the II-IV-V-VII chords together as you know, so maturally I play a lot of F# Lydian (the same as A flat Mixolydian) lines over that flat 5 chord. (A flat7). What this is actually doing, is giving you the most half step resolutions into the I (G Maj7) chord, correct?? (The half step being the strongest resolution) I meanF# Lydian to G Lydian, every resolution is the strongest! (Each chord tone resolves up 1\2 step.) Now what I am finding, is what sounds great, is to use the same basic theory, but in reverse. Instead of using the A flat7 (flat 5 of D), use A flat Lydian. This gives you a 1\2 step resolution going down on every chord tone. (A flat lydian, resolving to G Lydian) It sounds great, and I have gotten it from Benson lines. Is there any theory that explains this, or rule?? I have never heard of it, but it is used all the time, and sounds smooth as glass. Basically the same thing, and as Martino and kenny garrett do all the time, is use E flat DORIAN over the D7, instead of the typical Eflat Melodic minor. Then the E flat Dorian moves up 1\2 step to E Dorian on the G Maj7 chord. (E Dorian-same as G Lydian). Gives that upward 1\2 step resolution again. Anybodys thoughts would be greatly appreciated!