The sound comes from Alfred Hitchcock's 1960 thriller Psycho, scored by Bernard Herrmann. Its shrieking strings accompany the shower scene murder of Marion Crane and became one of cinema's most imitated horror cues. Herrmann used only a string orchestra, with violins stabbing at high registers to mimic screams and knife blows. The moment was widely parodied in television, cartoons and later horror films, which kept the cue in popular culture for decades. Today it works as instant shorthand for danger and insanity, recognised even by viewers who have never seen the full film.