The excerpt is at 0:23 and ends at 1:31...try to ignore the disturbing sound effects. I believe the original was a lullaby by a famous composer.

Shadow Man Soundtrack - Asylum: Playrooms - YouTube (http://www.youtube.com/watch?v=LsHA1DJ_ya4)

Thanks, ~ Z

- - -
Answer: Brahms Waltz in A-Flat Major, Op. 39 No. 15 - Evgeny Kissin