John Williams composed the five-note motif for Steven Spielberg's 1977 film Close Encounters of the Third Kind, where humans and extraterrestrials exchange the short musical phrase as a form of communication. The notes became one of cinema's most recognisable signals for alien contact, quoted in parodies, commercials and science-fiction homages for decades. Online, the clip is now shorthand for a strange arrival or an unexpected discovery, which is why editors still reach for it whenever a moment needs instant mystery without a long musical build-up.