I am, of course, always open to correction, Noreen, so don't apologise for that. But on the strength of what you have said so far, I am not persuaded.

If single/double can indicate notes per bar, how does this work when the notes per bar varies within a single tune (as invariably is the case)? And incidentally, not all jigs are 6/8. Slip jigs are 12/8.

But I admit I am puzzled. Why are some jigs called double jigs, given that none seem to be called single jigs, and all seem to have section repeats? And why are some reels called single reels, since none seem to be called double reels,and given that many single reels lend themselves to section repeats (which they usually get)?