Can anyone recommend any dark and foreboding music?

Anything I would want would be along the lines of "The Imperial March," from Star Wars, the theme from Dragnet, the theme from Jaws or anything like that. It must be a tune that implies that bad things are coming (Darth Vader, the cops, a shark, etc.) so as to warn anyone to be on alert. Think along the lines of your mother-in-law walking up to your front door or your boss coming out of his office to "have a chat" with you.