On Fowler, Steve and Jim will know this, but for the benefit of anybody who hasn't looked into it, what Fowler says is this:

'The lack of any extensive study of the evolution of ballad style cannot be blamed entirely on the tyranny of Child's edition. To a considerable extent this deficiency is attributable, I think, to an excessive current regard for the supposed autonomy of the oral tradition. It is very commonly assumed that the date of the manuscript or printed collection in which it appears can safely be ignored, unless perhaps the date is so early that it can be used to impress the reader with the antiquity of the ballad in question. Although I do not want to be rigid about it, my aim is to adopt precisely the opposite attitude. I shall assume that a given ballad took the particular shape it has about the time it was written down, unless there is specific evidence to the contrary. It is only in this way, I believe, that a literary history of the ballad can be written.'

"carouse with the sweepings of the streets'. Better to stick with CAMRA pubs than risk it? :)