[Guinevere]

Apropos your discussion about American English and British English: it made me remember something Tolkien wrote in letter #58 (1944)

I found myself in a carriage with an RAF officer and a very nice young American officer, New-Englander. (......)
I did however get a dim notion into his head that the "Oxford Accent" (by which he politely told me he meant mine) was not "forced" and "put on", but a natural one learned in the nursery - and was moreover not feudal or aristocratic but a very middle-class bourgeois invention. After I told him that his "accent" sounded like English after being wiped over with a dirty sponge, and generally suggested (falsely) to an English observer that, together with American slouch, it indicated a slovenly and ill-disciplined people - well, we got quite friendly.

I've recently bought "the J.R.R. Tolkien audio collection" consisting of 2 CD's with Tolkien reading from the Hobbit and LotR, and 2 CD's with Christopher Tolkien reading from the Silmarillion. I enjoyed hearing their voices tremendously! I too noticed the rolling R's .
(Btw did you know that Finarfin and Fingolfin have the stress on the middle syllable ? that was new for me.)
The Quenia in Galadriel's poem sounds rather like Italian to me, though Quenia is inspired by Finnish. Italian is the language that sounds most beautiful to my ears, but Tolkien's English - especially the "archaic" direct speech seems beautiful to me too. Although I don't really manage to separate the pure sound from the meaning of the words...
I studied for my CPE in London, but I lived then with an American family, and it was their way of speaking that stuck with me... , so that's "everyday" language to me, and the way Tolkien talks seems somehow "nobler" to me, but I guess that's just subjective.