Here's what I found on your question. Anyone, please feel free to expound if you have additonal knowledge.
The Celts split into the Irish and Scottish some time ago, but they still quite often harken back to their original singulaity. Pipes and kilts, both Irish and Scottish, stem from the Celts and Celtic traditions. They are very closely related, so interchanging them is quite common. Many Irish actually have Scottish bagpipes played at their funerals. |