whats the song playing throughout movie

Rating: 8/10 (30 December 2007)

i really liked this movie. even though it was just 28 days later with will smith in it... to be fair though i actually did prefer this version and i cried my eyes out when he killed himself at the end for the good of mankind...
however i felt it was a bit slow moving and also the lack of dialogue, although understandable, did bore me at times.
i also really liked the ending, i don't understand why everyone is saying the end is crap? whats wrong with the ending? anyway, my point was, there's this piano music that sounds really sad playing at various points throughout the movie. i really liked it and wanted to know what it is called?
thanks