Devil's advocate here, but surely folk singing always involves a bit of tinkering as part of the whole process of "take it, sing it in your own voice, and pass it on".

I accept that if you're collecting and publishing something as having been collected from a particular person in a particular place who sang it in that way, then there's a duty to report and be as rigorous as you can about it. And I suppose in some of what he did, Lloyd was a 'collector' in this way. But I think that the problem with saying that something has to be performed with a very particular reality, as it was sung at a particular time, is that it ceases to be folk music, it becomes archival material, ossified and locked down.

My rule of thumb is to hope for clarity, rigour, and honesty from collectors (within the bounds of realism).

But equally, when people are acting as singers, not as collectors, then I allow people who are singing to do what people have done for generations - make it their own, give it new life, and pass it on.

That's certainly what I do - I don't pretend that anything I sing is "as it was in 1880". I'm not a historical reenactor, I'm a singer.