This clip is widely recognized online as the Haachama scary background music, but the underlying track is the royalty-free piece ChoirWaltz by PeriTune. It became tied to Haachama through fan edits, horror compilations and VTuber meme videos that used the song to mark a sudden shift from cute or chaotic to genuinely eerie. Its staying power comes from that contrast: the waltz rhythm sounds almost playful at first, while the choir gives it a disturbing edge that suits ironic horror editing.