Audible Beauty

Yes, it was the Fellowship trailer - http://www.lordoftherings.net/trailers/ - the second half of it.

Edit - yes, it was "Gothic Power" - I understand that this is a well-known track - thank you.

I've noticed a haunting choral track in the trailers of several movies (the remake of War of the Worlds and Lord of the Rings - The Two Towers as examples) that seems to be used in the initial trailers during action scenes, and is then replaced in later versions of the trailer by more movie-specific...