Modal interchange: Lydian Dominant

Lydian Dominant is a Mixolydian scale with a ♯4:

1 2 3 ♯4 5 6 ♭7

Lydian Dominant interchange happens from time to time, and usually by borrowing a II7 chord. It’s got a nice driving brightness which brings additional energy but without being too loud about it.

Usually the II7 chord is used as glue, a brief flash of brightness on the way to somewhere else. You don’t usually hear it as the defining sound of a section. (That’s why it’s hard to find tutorial examples).

You can also just hear a ♯4 in the melody (going up to a 5). That’s Lydian Dominant too, though of course a subtle version of it.