I don't know if I'm the only person who does this, but I go out of my way to pick appropriate music for what I'm working on. I have a large collection of film scores, classical music, rock, etc. And depending on what I'm working on, I'll listen to different things.
I often wonder if this is a good thing of not? While writing, does it influence me to be more like the film that I'm listening too? While I'm editing a script, does it make me like the script more because it brings up memories of something else I enjoyed? In other words, does outside media influence one's perspective? Does it alter my perception of what I'm working on?
I'd think it would have to to some degree. But I also think it sets my mind in a more focused way towards a goal and it might get me to concentrate a bit better. I don't know for sure. I don't think there's a way to know for sure.
But I do know it makes working a bit more fun and that Phillip Glass is a genius.