Bernard Herrmann composed this whistled theme for the 1968 British thriller Twisted Nerve, where its innocent sound contrasted with the film's disturbed central character. Quentin Tarantino later revived it in Kill Bill Vol. 1 from 2003, when Elle Driver whistles it while disguised as a nurse and walking toward her target. That scene turned the tune into a widely recognised signal for approaching danger. Online, creators have reused it for horror edits, prank reveals and villain entrances, keeping it popular because the calm whistle feels more unsettling than an obvious scream or dramatic score.