It depends on the tune itself. The one that is most familiar to me, as an
American, is Money Musk. That is a strathspey in a very traditional form.
But after it emigrated to the US it became a driving reel, key of A.
Takes a reasonably good musician to play it and it is only done for the contra
dance Money Musk. I recently had to play Cauld Kale and the arranger took
a couple of reels and recreated them as strathspeys, plus 2 more
strathspeys and made them into reels.
Sylvia Miskoe, Concord, NH USA