The development of technology and movie industry has changed expectations of music on movie. Older versions of soundtracks, there were pure melody which had to intense emotions. Of course still it should be, but movies give new responsibilities to the music. Audience and movie crew expects more than pure melody, because they are used to hear it and they need more than it. In addition, technology has changed the frames, transitions and visual effects. So that music was forced to support these new technological elements with new musical idea which is “Orchestral Effects”. From the 2000’s, movie industry with the support of Hollywood has been developing in technical terms, like lots of visual effects. They have been paying attention to those effects and they want music also pay attention to visual effects.
Composers’ cure to solve this issue is creating big crescendo chords and sharp endings. (Which for mainly written in brass section) In action movies (which are Pirates of the Caribbean, James Bond, The Dark Knight Rises, Sherlock Holmes, Mission Impossible and etc.) this style can be easily shown.
The other way of creating effects with orchestra is glissando chords. This style is generally for stressful scenes. In addition, fast rhythmic motives are tools for creating effects.
Movie composers have to create “new music” for movies, because technology forces to do that. However, movie composer have limits about composing new music. It means, movie audience doesn’t expect musical master pieces from movies and most likely doesn’t have much experience of polyphonic music. If composer goes beyond the limits, all production can be collapsed, because the most important point of success is meeting the expectations and providing balance between movie and music.