I'm sure it normally means they aren't sung, but of course it doesn't mean they can't be sung. As I said, I am going to mark these "recitation" in the list, but not remove them from the list. So if anyone FINDS music to them, they'll still be there to be posted...

For example I KNOW I have heard Deck of Cards sung, and found a reference the other day to a sung version of three hapence a foot.