Here's Bert Lloyd reverting to 'purist':

'the folk traditions have never been the fixed monolithic structures that some purists would have us believe. On the contrary, styles of folk music have constantly changed, down the ages, according to changes in the fate of the labouring people who carried that music. Folk-Art traditions do not stand still any more than fine-art traditions do, which is one reason why the romantic chasers of the "authentic" in folk song so often find themselves pursuing a will-o'-the- wisp.'