Or, how I journeyed into the odd world of superimposition.
This song started as a lick that I played on my guitar, which just happened to be in A Dorian; Most of the song is in this key. (Don't forget that A Dorian is also G Maj, and E Min.) The main exception is when the song turns into E Phrygian. If you are new to music, you may wonder, "What the hell? That's not diatonic!" Yes, strictly speaking, it is not.
To get new colors out of a song, superimposition is not a bad choice. You could think of this Dorian mode as an Aeolian mode instead, and then move up 1 and 1/2 steps to the relative major; afterwards, you could figure out that E Phrygian is the diatonic mode in C Major. The possibilities are endless!
Also, this is not technically superimposition as it is normally used, but if getting a new color is what you want, I would encourage you to experiment.