Regardless of its purpose, the humpback-whale song is the most complex piece of nonhuman composition on earth. Whether it's art, prayer, or booty call, the humpback song is an amazing thing to experience firsthand, and I suspect that even once the science of it is put to bed, it will remain, as long as they sing, magic.
Author's notes : Science and Magic - Fluke, or, I Know Why the Winged Whale Sings (2003)