The film "The Exorcist" scared the fuck out of me as a 14 or 15 year old. The bits I managed to watch anyway. I remember cowering between the theatre seats and glancing occasionally through webbed hands. I'm not sure what the rating was at the time but I probably shouldn't have been there - it haunted me for years! I refuse to watch it even now.
The music that accompanied the film was Mike Oldfield's "Tubular Bells". Luckily it doesn't recall the horror of that film when listening but it's just as poignant.
What's remarkable about this masterpiece is Mike Oldfield was just 19 when he recorded it!