Hobbits: Folk Metal. They love their riffage spliced with fiddles and accordions, and lyrical content about simple living, food and ale.
Elves: Death Metal. They're pre-occupied with the fading of the world and all such bleak matters. Fast or slow, this genre suits them perfectly.
Rohirrim: what we call Viking Metal. Though specific characters in the subject matter may have to be altered somewhat, the basic feeling of riding forth to battle and revelling in the slaughter suits Rohan well.
Gondorians: Progressive Metal. Cleverer, more intricate and thoughtful than other types, such inventive music would be greatly admired in Gondor.
Ents: Drone Metal. Because they have patience, they will be happy to go for hours at a time without a single guitar riff.
Orcs: Deathgrind. Painfully fast and loud, lyrical content appeases their bloodlust. Gets them into a frenzy before war.
Valinor: Thrash Metal. Because it's always party time in Valinor.
Trolls: Troll Metal. Of course.
Istari: Black Metal. Because they have reached the heights of music.
