It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
You are referring to something that is called a Sting
A sting is a short musical phrase, primarily used in television shows and films as a form of punctuation—for example at the end of a scene, or as a dramatic climax is imminent. It can be played on a variety of instruments and performed by a group or orchestral ensemble.
Another form of sting, often incorrectly called a rimshot, is used only in comedy and played just on percussion instruments (such as drums or cymbals) as a payoff after the delivery of a punchline.
A musical sting can be used in drama, comedy, horror or any genre, and in radio and television advertising. It is a part of the music director's lexicon. It is often used to build tension.
The origins of the Sting are deeply rooted in classical music - namely Wagner - but when applied to drama they were first heard on Radio Shows.