Jon confesses, “I forgot to do this in the autumn and there’s no sensible place to put it now, but it’s such a great chorus song it seems a shame to miss it off. So here it is.”
According to Bert Lloyd’s notes at Mainly Norfolk this actually two songs welded together celebrating both sheep shearing and the harvest. The latter naturally falls into autumn, but the sheep shearing of the title is more early summer to prevent the animals overheating during the hottest months. Sheep would have naturally moulted, but breeding to develop the yield of wool now means that human intervention is needed. So strictly speaking this could probably have gone into June on the basis of title, but the harvest bolt doesn’t really work there. Anyway, timely or not it’s a rousing chorus and I like the suggestion that the verses were repeated until all glasses (or tankards) were charged. I’m not sure about the suggested pagan link other than to say I would be more surprised if harvest festivals were proved to be a recent invention.