There's a good reason it is so somber. The music was written for a song of a suitor whose unrequited love was rejected. The sad music was adopted for this song about Bonnie (Handsome) Prince Charlie of the Scots who had to flee to exile on the Isle of Skye after the disastrous Scot's defeat at the Battle of Culloden. It seemed that the Scots cause was lost, and many good men, noble and common,had fallen. Grief inward and in every surrounding direction.