Just incase, it's the first slow piece at the start not the more energetic second piece used toward the end of the trailer, and as common sense would suggest, the advert is showing on Channel 4 and probably the other Channel 4 channels.
Note the they could be two very different parts of the same song but I wouldn't be asking if I knew that. Would I?
![Razz :P](./images/smilies/icon_razz.gif)
Thanks for any help guys.