I thought I’d also mention that piece of music early on. That was the bumper music they had before commercial breaks on the network showing. They would fade to the Exorcist title card before the break.
The music there was shown at the end of the scene that the priest discovers the desecrated Virgin Mary statue. The movie version of the statue was replaced with a close up shot of the statue’s face, broken and painted on. I thought, along with the music, it was actually creepier than the theatrical version.