I don't know if this is the same advert I've seen, but if the song goes "happiness...happiness..." it's "Happiness" by The Blue Nile, from their album "Peace at Last".
Those nice people at the Visit Scotland website got in touch with me, so thanks to them for this info.
The music was specially comissioned for the adverty, and it's by Paul Mouncey. Unfortunately, the track isn't titled and hasn't been released yet.
The following website might be of interest:
http://www.nahoo.org.uk
Just in case you cant get the song out of your head and cant get over how good the video is, then goto this link and you can watch it online...
www.scotexchange.net/promote/spring-campaign.htm
or click on the following link
http://easylink.playstream.com/marcat/40s.rm
ha ve
fun