I present you with four links (via Mike Sterling's Progressive Ruin [1]):
And yes, they're songs, with lyrics. Bet you didn't know the Superman Theme had lyrics, did you? Or the Jaws Theme? But they do.
Or at least they do as Goldentusk [6] rendered them (he reminds me of a cross between Wierd Al Yankovic [7] and Rob Morrow [8]) and they come across as what you might hear in a musical version of the respective movies.
[1] http://www.progressiveruin.com/2007_02_18_archive.html#4453947604360836589
[2] http://www.youtube.com/watch?v=ELNh23yRiJc&eurl=
[3] http://www.youtube.com/watch?v=aCHtdh1snzY&mode=related&search=
[4] http://www.youtube.com/watch?v=GheAd59anbU&mode=related&search=
[5] http://www.youtube.com/watch?v=Xc17zmeMlSI&mode=related&search=
[6] http://www.youtube.com/profile?user=Goldentusk