Diane Easby above mentions that Woody Guthrie's daughter asked the Bard of Barking to set some of Woody's lyrics to music and seems to think that this qualifies him as an expert on folk music.
I remember watching part of the resulting TV programme and was most amused to hear a well known song that pre-dates Guthrie being sung to a new Bragg tune.
The fact that Woody had the lyrics of a song written down needn't mean that he was the author. I have the words of many songs written down without music. I didn't write one of them.

As pointed out above writing a protest song however good or bad still does not make you an expert on folk music.

The important thing is that folk and folk flavoured music is getting exposure on TV even though we can't see it because we are at morning service. However there many knowledgeable people on the scene that could have added more IF talking heads are needed.

Hoot