Dun, Dun Duuun! Listen to it below. The three-note musical sting of suspense is everywhere and has seemingly been around forever. You can hear it on screen all the way back to Disney's Fantasia (1940) and in countless radio dramas before that. But where did it originate? From The Guardian:
Suspense, an American horror show broadcast on CBS Radio between 1942 and 1962, was filled to the brim with sound effects and dramatic stings. Just over three minutes into its first episode (after bells, the sound of a train, and plenty of piano), a three-beat sting lingers on its last note when a man discovers his wife is potentially an undead poisoner. But it's difficult to pinpoint the very first on-air dun dun duuun, and it's likely the musical phrase predates the radio. [Media professor and Terror on the Air! author Richard] Hand says the medium tended to adopt already popular tropes to entice listeners. "They imported that musical structure and musical language," he says, pointing to Victorian stage melodramas.
In fact, Patrick Feaster – an expert in the preservation of early sound media, and co-founder of the First Sounds Initiative – argues that dun dun duuun could have been a cliche long before the advent of radio drama. Though he doesn't know when or where the three duns arose, he points out that stings "that work in much the same way" appeared in the 1912 melodrama parody Desperate Desmond by comedian Fred Duprez.
In a recording of the sketch which can be heard on the US Library of Congress website, Duprez mocks melodramas by telling a story and rebutting the incongruous sounds that play between the action (when a villain enters with a dramatic sting and a clip-clop, he exasperatedly says, "Not on a horse! Just on his feet!").
Though the stings heard in this sketch are single duns (sans the follow -up dun and duuun), Feaster says: "It seems stinger chords must have been entrenched enough in melodrama by 1912 to invite parody." He guesses that the three-beat version may have then come to be preferred for satire, "because it's more conspicuous than a single all-at-once chord would be."