There's currently an advert on Film Four, with a song in the background, that sounds like it could be the theme tune of a children's programme. I used to have it on my computer, but I can't for the life of me remember what it's called.
is it a piano tune? if so then it is prelude cos i played that haha. i know they used prelude a while ago but i dunno if it'll be the same. probably not xxx