The melody most people call the Exorcist theme is from Tubular Bells by Mike Oldfield, a 1973 instrumental piece prominently used in the film The Exorcist. Because of that association, the excerpt became shorthand online for demonic horror, eerie reveals and unsettling comedy edits. It still shows up in short videos, prank setups and ringtone searches because a few notes are enough to signal classic horror immediately, even to people who have never watched the full film.