what the ******* does the Bard of Barking know about any carolling traditions?

On another hand, what do you know about Billy Bragg or the Unthanks in order to preach so knowledgeably about their tastes and motivations? If they're asked by the BBC and they have an enthusiasm, why shouldn't they help spread it. The end result might even reach beyond a few self-appointed expert musicologists. Is this a bad thing?