Thriller/Mystery Genre - Music

 Music

A typical convention of music in the thriller/mystery genre is to create suspense. Usually the music will be non-diegetic so only the audience can hear it and not the characters. The music can foreshadow something that is going to happen, for example a song would have a fast tempo that only the audience can hear which will create tension and mystery because the characters have no indication of what is coming.

Diegetic sound is when both the audience and characters can hear the music. Typically it would be played on the radio, by a band or somewhere in the story's world or setting. 

As the character can hear it too it might affect their mood or create an emotional response from the watcher.

Synchronous sound or parallel sound is when the genre of music is appropriate for what is happening on the screen, matching it. For example fast-paced up-tempo music would be played in an action scene or in a sad scene would feature slow melancholic music. Also can be used so the beat of the music can match the pace of the editing. In thrillers the music is likely to be sinister and suspenseful, matching the threatening atmosphere, or fast-paced matching a character's panic or them running from a threat.

Contrapuntal sound is for music that seems to go against or contrast with what is happening on screen. For example a lullaby for babies being played in a horror or thriller film. It is often used to confuse, unsettle or disorientate the audience or maybe to reflect the feelings within a character, and is therefore very common in the thriller genre.