what was the piano piece played in halo 3?

[Matthew Perry]

just curious what it was called so i can try to find a manuscript for it. its not the one in the believe trailer. i have it on my ipod but it dosnt have a title since all my songs are labeled track08 for example

thanks
special thanks to hasham yourrsef, because his answer help me so much. its not like the was a soundtrack released or anything. and people really take notice of the copy-write laws these days.