Music of the Ainur: Rap? Country? Opera?

[doug*platypus]

We already know what Durin's Bane the Balrog played:

Drums, drums in the deep.

I read Letters of JRR Tolkien recently (definitely worth a read!), and I'm convinced he only liked Classical and Opera. Hardly surprising since he was born in 1892. It was funny hearing him insult the music of the 1930s as being so new and brainless, when these days a lot of us would call it old-fashioned! Sometimes it's easy to forget that LOTR is already 50 years old.