Sound is something which becomes iconic within a horror film. You would be able to identify films without watching them just by identifying the music. For example most people would be able to identify Jaws because of its famous theme tune, likewise with Psycho. Sound in Horror films is most commonly used to show the threat of danger and allows the viewer to identify if there is a threat.
Music in Horror Films contains something called non-linear sounds. This includes distorted notes and sounds similar to blowing too hard into a trumpet. Non linear sounds are used to enhance the emotional impact of scenes. Non Linear sounds can be created when somebody/something is put into a position of danger, this taps into the instinctive fear of the viewers and causes the fear to be created.
Something which has recently been used in horror films is the use of children's nursery rhymes. The nursery rhymes when played slowly can sound quite sinister and give the sense that any age group can be under threat. This shows how much of a part sound plays in horror movies.
The movie clip of above shows just how important that sound can be in horror movies. Without the sound in the clip it wouldn't be as scary, the sound creates all the tension and suspense in the clip as it signals the threat of the shark as it closes in on its prey. This increasing volume of music is probably the most iconic and most frequently used in horror movies.
Violin instruments are also often used in horror movies to create an eerie and tense feeling in the film. This is used in films such as suspiria and exorcist which have become famous since the release. The music in horror film also can determine what genre the film is, for example the opening of The Shining can be interpreted as a different genre if you were to change the music in the opening sequence due to the ambiguity, the sound is what allows people to decode whether it is a specific genre.