Okay so there aren't a heck of a lot of songs written specifically about Time Travel or Alternate Universes. There are however a number of songs that discuss the nature of time, or when liberally interpreted could imply time travel. If you don't believe me, I've included a few here with my own interpretation of the lyrics.
There are also a number of music videos that have used time travel and alternate universes as a theme which I've listed below as well.
Good Ridance (Time of Your Life)
I Miss You
It's All Been Done
It's All Right With Me
Once in a Lifetime
Return to Andy's Anachronisms Home