The techniques of different directors are very different, and people have different ways of expressing ideas in film. I'm happiest when working with a director as I would be if I were an actor. I'm wanting to provide a really good performance.
You don't always want to be using the music in a way to express ideas inherent that are on the screen. You might want to work more around the fringes of the story, and work more with the subtext, and add more depth to the story through the use of music.