This is the famous theme from the movie "The Snowman", composed and lyrics written originally by Howard Blake. It has been covered by other artists; my favorite is Nightwish' arrangement.
The music appears in the movie in a scene in which the snowman and the boy fly from the home to the North Pole to meet Santa Claus. (Fantastic three-dimensional hand-drawn animation sequence, by the way... =)
I like this stuff for a reason... I love dreamscapes!
The lyrics used to be here. I removed them because of copyright reasons. If you think this was a Wrong Thing to Do, node them back, but ask the permission from the author.