What are the most beautiful pieces of classical music you know?

First of all, the music in LOTR and Last of the Mohicans is not classical music. However, if it is sublimely beautiful music that you are looking for then might I make the following recommendations: Preludes to the first and third acts of "Tristan und Isolde" by Wagner. Fantasia on a Theme by Thomas Tallis - Vaughan Williams. Also Sprach Zarathustra, op.30, - Richard Strauss. Symphony No.4 in F minor, Second movement - Tchaikovsky Symphony No.6 in B minor, Second movement - Tchaikovsky Polovtsian Dances - Borodin

I personally don't think you can go wrong with ANY of the works of these classical composers: Mozart, Handel, Tchaikovsky, Chopin, Strauss, and Bach. Have fun with your film :o)

Don't say a word, just listen.

second or slow movements of symphonies and piano concerto's are probably what you're looking for chopin nocturne's are nice if you want piano pieces but maybe the slow movement from elvira madigan (mozart's 21 piano concerto) or the third movement of brahms second piano concerto is what you're looking for

Oh Mozart's requiem is BEAUTIFUL... I love it. Dont know if it's what your lookin for but... hey :)