I have been trying to understand these things for years. Last night I did some research and got to where it made sense, to me anyway. Epiphany! I looked at the usual mode charts In C of course, with all the Greek or Latin names and i realized they are the same scale patterns I've been using since I was a kid. I said OK i'l play along, so I memorized the names for each pattern instead of calling them box 1,2,3,4,& 5. I was playing Mixolydian, Phrygian, and they didn't sound any different at all with the new names. Same fingering same scales different label. So I tried starting with C and ending with C and thought that was Modal. Still no real flavor change...then it sruck me to just plug in the Mixolydian into where the Ionian was and play from C to C. Thats when it all made sense. I could do this with all of them. It seems (I may be wrong ) but, when I was playing Mixolydian it was basically the same as my box scales in the fey of F#. So are modes just playing in another key within the parameters of starting and stopping with the notes of the key that youre in?