- For the area with the same name, see CORE.
"CORE" is the 65th track in the Undertale Soundtrack. It plays when traversing through the technologically advanced part of Hotland, known as the CORE. It is a remix of "Another Medium," and "Death by Glamour" both of which take a motif from "Waterfall."
- The song is sustained throughout encounters in the CORE, rather than "Enemy Approaching" playing. This was likely inspired by the similar nature of the Ocean Palace from Chrono Trigger, one of the major inspirations for Undertale.
- The in-game version of this song is played at a higher pitch (lower-pitched in the Genocide Route) than the soundtrack version. It also plays at .5 speed.