DOES ANYONE KNOW.. (TWILIGHT PEOPLE)?

Im asking this for a second time.. someone please know.. If any of you saw twilight last night.. When Bella goes over to meet Edwards family.. they go up into his room.. she asks him what he's been listening to and she puts in the CD.. now a piano piece plays.. its not bellas lullaby or whatever.. its an old beautiful piano piece.. she even responds to it and says the name.. it starts with a C.. Ive heard it in weddings and all sorts of stuff.. if anyone can answer correctly.. i'll give you an easy ten points.. thanks so much