[Morthoron]

Somebody had mentioned Queen earlier, and there are a slew of their songs that fit different Tolkien characters (at least title-wise):

The WitchKing -- Death on Two Legs ('You're just an old Barrow Boy...)

Arwen -- Who Wants to Live Forever

Frodo -- Seaside Rendezvous

Gimli -- (Just Waiting) For the Hammer to Fall

Legolas -- My Fairy King or The Fairy Fellers Master-Stroke *swoons*

Galadriel -- White Queen

Ingwe -- In the Lap of the Gods

Gandalf -- The Prophet's Song

Sam -- Keep Yourself Alive

Sauron -- One Vision

Lotho Sackville-Baggins -- Tie Your Mother Down

Morgoth -- I Want it All

Elwing -- Spread Your Wings

Gollum -- I'm Going Slightly Mad

Denethor -- Put Out the Fire

Et cetera and so on...