As Mysha said a couple of years ago, we don't know if JOH was a cumulative song. Although in their sleeve notes the Watersons mention it with 12 Days of Xmas they call it a forfeit song, i.e., I suppose, involving a game of some sort. I always thought a game had to be part of it from the last line - "Who's going to win the girl but me?" Blind Man's Buff perhaps?