Modes are derived from major scales, traditionally. Understanding traditional harmonic concepts can expand any POV. A chord is a chord. It's function may depend on what preceeds it or follows it. Any given sound is a function of harmony. X=X, the fun part is making X= delta quad phlange.
American music is tradition with a major twist. That twist is sort of against tradition, which is American. Take one major scale and play it from any one point. You have modes.
Each any one point has it's own harmony (chords) and function. Look at modal scales as a mental and aural sidestep of major scales and their appropriate harmony.
It's like reading a broken ruler, at any point, 1 inch is still one inch. The musical alphabet (ABCDEFG) never changes.
Another view of modes are at
http://members.tripod.com/~griphon2/index-11.html

Hope this helps.