What is the name of the song played in the movie "The Box"?

I've watched the movie several times, and I can't seem to get this song out of my head. It's played by a piano in the beginning, and later the full orchestra comes in. The song I'm looking for is really sad, and it has no words, just instruments, and it's repeated twice within the movies. Once when Cameron Diaz, and her husband are getting ready for a party, and the other I believe it is played towards the end. Thanks in advance for all of your help!