The last few years, while watching a movie in a theater, I had the same experience happen to me several times and those experiences tend to stay in my memory associated to the movie, making the movie alive at the same time as the music.
Obviously, the first it happens to me was for the music of "The hours". Obviously, the composer was Philip Glass himself and the music blended so well with the movie. Each reinforcing the other to become only one.
The last two examples came later. The first one was the music of there will be blood. I could not stop listening to this music enjoying every note of it and then when the name appeared. I noted to myself. Interesting he has the same name as the Radiohead guitarist just to realize later that they were the same person and the second one was yesterday watching a single man with a young composer that I didn't know: Albert Korzeniowski. The songs remain in you and you spend your time thinking about listening tot them again and again.
Three great music scores by three great artists for which I am hoping to hear more of in the coming years.