Re. the Tunnock's Caramel Wafer song, Adam McNaughtan was privately commissioned by the family to produce something for the centenary celebrations/ birthday of the current chairman -- but it was so catchy that it was even used in some of the tv adverts for a short while.

When sung to an unsuspecting audience, there's always a grin of delight when reaching the final few words of each verse. And a Scottish audience, familiar with the tune, will happily join in with those words after verse 1.