The dickhead who started this thread began by talking about tunes and then didn't discuss anything but songs thereafter.

The dance music of the British Isles has been accompanied for centuries. Illustrations or descriptions of performances as far back as the Middle Ages mention drums and bass instruments.   Almost as soon as Scottish dance music began to published in large volume in the18th century, it was published with bass lines.   Virtually all the current Scottish dance tune repertoire (except pipe tunes) was conceived for textures including a cello or left-hand keyboard part. It mostly sounds crap on a solo melody instrument (and so do pipe tunes if you take the drones away and put nothing in their place).

This does NOT mean these tunes have canonical chordings like modern pop tunes. They were not conceived with the harmony first; the chords or bass vamps simply serve to delineate phrases in the dance, they don't "progress". It doesn't matter a great deal what the chords are so long as they change with the right timing.