What Makes Horror Movie Music So Scary?

From the high-pitched screeching of the famous “shower scene” in Hitchcock’s Psycho, to the ominous and repetitive “dun dun dun dun” as a gigantic shark lurks beneath a swimmer in Jaws, directors have long used music as a powerful tool for scaring the audience. But what is it exactly that makes some music so scary? And is our reaction to it down to nature? Or is it influenced by our environment and prior experiences?