Karen O was on the soundtrack, I knew you were talking about the score itself. The movie isn't that depressing, except if you're talking about when the monster is standing on the island howling at the boy...
That gets me EVERY time!

“Whoever will be free must make himself free. Freedom is no fairy gift to fall into a man's lap. What is freedom? To have the will to be responsible for one's self.” - Max Stirner.