[bazza]

I should add, of course, that shuffling a number of setlists as described wouldn't change the order of pieces in each mini-set. It would shuffle them by title of set - i.e. where that title is actually made up of two or more tune names, as in 'Mason's Apron/Collier's reel'.  The shuffling would not affect the content of each set.

Presumably a band might also have several sets stored for different purposes, e.g. a wedding set, a Christmas party set, a concert set . . . .   But, as you imply, that sort of shuffling would probably not be as much use to them as it would be to us folkies.