Drops of jupiter is not a good text. It's a pretty song, sure, but you'll have a hell of a time explaining the meaning in an essay.
Basically what it's saying is that he's afraid the journey she has made has changed her, because of all the amazing things she has seen. But it's short on super-cool sounding english techniques and so you shouldn't do it.
The only song that I would identify as a good text for ANY unit would be American Pie for changing worlds, as you'd use the transition in the music as a major technique. But other than that... just don't do a song. Ok?