Morricone seems to have taken quite a few pages from Komeda's score for "Rosemary's Baby" here for the soundtrack to this Dario Argento serial killer movie. This track features some creepy heavy breathing, cascading dissonant piano notes, and some of the scariest "la-la-la"-ing ever committed to wax. I've never seen the movie, but based on the record, I'm pretty certain that it would scare the hell out of me.