Daisy Bell began as a late 19th-century song, and it later became widely recognizable to modern audiences through HAL 9000 singing it in 2001: A Space Odyssey in 1968. Creepy versions spread online because the melody is so familiar that slowing it down or changing the tone makes it feel uncanny. It still shows up in horror edits, retro internet memes and unsettling video essays for that contrast between innocence and dread, much like Hello darkness my old friend is used to flip a scene's mood.