The original theme comes from Stranger Things, the Netflix science-fiction horror series that premiered in 2016, with its distinctive synth score composed by Kyle Dixon and Michael Stein. Darker, slowed-down versions began circulating online as creators reused the melody for horror edits and suspenseful short videos, especially on TikTok, where the familiar tune instantly signals that something strange or frightening is coming. Because the melody is so recognisable even when slowed, it still works as shorthand for mystery, the Upside Down and creepy reveals years after the show first aired.