Exorcist II: The Heretic has the reputation as “one of the most notorious disasters in movie history” but it boasts an impressive Ennio Morricone soundtrack. Lacking even the great Brad Dourif and the image of an old lady crawling across the ceiling that factors so heavily into the enjoyment of part three, most people agree that the haunting music is the film's only worthwhile element.
I've been informed that this is a rare find, my friend Shaun purchased his CD at the excellent treasure trove Amoeba Records, but you can also pay a higher price on an Amazon import. If you're a fan of creepy Morricone dissonance and haunting melodies, it's worth the investment and time to track it down. It bounces from soft, almost romantic sounds to frenzied intensity. Definitely makes the work day more dramatic.