If archangel is correct, and the tune has something to do with Struan Robertson, then the question is which tune?
Major Donald Struan Robertson (Scots Guards Standard Settings, vol. I) is a 6/8 jig.
Struan Robertson (same book) is a 4/4 strathspey.
Struan Robertson's Salute (Piobaireachd Society Vol 8)is a 4/4 piobaireachd, and would be the most likely candidate for a tune that might have existed in 1314. Unfortunately, it is not the song on the Amazon CD. If you can find a copy of The Classic Collection of Piobaireachd Tutorials, Vol. 1 by PM Donald MacLeod, Struan Robertson's Salute is on there. Note that it appears (I don't have the CD and can't confirm) that the pieces are done in Canntaireachd or on the PC, not the full set of pipes. It should still give you some idea of what the tune sounds like.