Wendy Carlos' rendition of Dies Irae combined with the utter isolation of the path to and from the Outlook Hotel set the uneasy tone of the movie perfectly for me.
Despite being a horror movie, the shots of riding down those winter Canadian streets on a bike during overcast while Keith Mansfield's Summer's Coming is playing is pure bliss to me
The whole sequence before and after the MGM logo. The black nothingness combined with the score to show how there was...nothing before the "big bang," then...the classic Also Sprach Zarathustra horns blow while the camera pans up to show the sun rising over the planets