The beauty of films is that you can tell a story and create a myriad of emotions and concepts in the span of a short time.
Setting the tone: Music sets the tone for a movie. It gives the audience an idea about the genre, level of intensity and the kind of movie it is. Even though it’s a subconscious effect this happens quite fast. Dialogue and video create two inputs; music creates a third input in the mind of the audience which helps them to think and interpret the scenes in a certain way. Sometimes this is made obvious and other times it is subtle.
Contrary thoughts: It is possible to create music contrary to the scene, which gives the audience a different perspective. This is often used in plots which have a twist. For example, imagine that a villain character is actually a hero and the film maker wants to convey that towards the end of the story. Music can help by creating a perspective from the audience’s point of view rather than revealing the character’s actual personality in the beginning.
Another example could be to use music for creating a false sense of anticipation and then backing off. This tricks the audience into thinking that something is going to happen, but it actually doesn’t.
Thematic Development: There is also scope for thematic development, as in it is possible to use a couple of musical themes and then develop them as the story progresses. Composers may use a variety of techniques to develop a musical theme, like increasing the size of the orchestration, developing the melody of the theme as the story progresses, etc.
Character themes: Character themes help the audience to understand and connect the dots as far as the plot is concerned. For example, if there’s a bad guy in the story and we have his character theme, every time he is about to come if that music is played, the audience gets a hint that something bad is going to happen.
Custom Sound Pallet: Analogues to musical thematic development, is the development of the soundscape for the movie. The pallet of sound used in a movie can be the collective decision of the director, producer and music director. Creating a unique blend of instruments and sounds give the film an aural personality. Its not always necessary to use new sounds/instruments for every project, but just by using the same sounds/instruments in a different way each time gives depth in the soundscape and makes it unique to that particular project. This has a subconscious effect on the audience and helps them to relate to the story better.
Perception of time: Pacing of the story and screenplay may be slow or fast depending on the director’s vision and film making technique used. The role of music here is to create movement and alter the apparent pacing of the video cuts. The perception of time can be manipulated by varying the tempo of the music according to the intensity of the scene. If this is not done effectively the story may appear to be draggy/sped up without it being able to retain the attention of the audience.
Dynamics: Every good film has dynamics. There are scenes which are lighter and scenes which are more intense. Music can emphasize on the gravity of the situations to the right extent. Sometimes even silence acts a powerful tool to help create dynamics. When there is no music, attention shifts to the Foley. Interplay between sound and music helps in creating an immersive experience where the audience is pulled into the story.
Expressing emotions: Music can do a lot more than just make you feel happy or sad. It can make you think and feel in a certain way about the characters, their dialogues and the storyline. This helps the audience relate to the characters better and it also subconsciously creates a perspective about the movie. The right music can help to accentuate emotions or create contrast. For example, if you have a more or less neutral scene with an expressionless guy looking out of his apartment’s window, the music can provide a hint about what the man is feeling or thinking.
Gluing scenes together: Films often have montages that help to tell parts of the story. These can be interpreted in various ways, so music gives the audience a better idea of how these scenes connect with each other and with the story.
Music helps to smoothen the video edit and blend scenes together to make the story flow better. However, its easy to lose the connectivity between scenes if the music is more contrasting than it should be.
Time period, Culture and Location: Music can also be used to enhance the characteristics of a location or time period. For example, if the movie is set in the 15th century and based in India, the music can help create the vibe of that era and location by clever use of traditional Indian folk instruments and musical styles influenced by the culture of that time period.
Mickey-mousing: This is an old school idea that dates back to the time when music was first introduced in film scoring. In this technique, anything happening on screen is coupled with a similar impact in the music. This is largely used in Charlie Chaplin’s movies, Tom and Jerry and Disney movies for kids. It makes the actions on screen appear more obvious so it is widely used in the comedy genre. You could think of this being more like musical sound effects.