Tolkien actually developed two varieties of Elvish.
Quenya was the High-Elvish language, roughly the equivalent of Latin in 18th century Europe.
Sindarin was a living language spoken by the Elves of Middle Earth and some humans, mostly aristocrats descended from the Dunedain.
This Klingon translation is one I've never seen before. LOL. Some one has a lot of time on their hands. Eventually some Tolkein fan will translate the BoM to Elvish.