Most days I wake up with a song in my head - but I prefer to think that it is in my heart. Something like Livingston Taylor's "Never Lose Hopet" or Ingred Michaelson's "Be OK" propels me out of bed and into the shower. Sometimes it's from the Mama Mia sound track (which my kids *love*) or from "Phineas and Ferb" (kid's show).
I heard that we have nerve cells that go both to and from our ears and brains so that we are truly "hearing" the songs that are playing in our heads. I know sometime a song is not welcome - perhaps it is only a partial song (or maybe just annoying). Try substituting with another song - don't just supress it.
I hope you have a song in your head (or heart) today to enjoy. If you want to, post to my Facebook page that song that you *like* most to be in your head.