Addition to below in response to the Cap'ns offensive suggestion above which I have just seen - I don't send anonymous postings - I'd demand an apology if I were a prat.

Whether Bob Roberts is or is not a traditional singer should be decided on a little more than 'gut reaction' (I'd try some Rennies for that). It depends on where and how he learned and sang his songs and whether the community he belonged to was a tradition bearing one. Personally I don't know enough about him to judge, but this is his CV from the BBC index.

"ROBERTS, Bob (A.W.)
Singer. Pinmill, Ipswich, Suffolk. 25.10.53 and 12.7.56.
Aged 46 (1953); a well-known sea adventurer. Was skipper of one of the last Thames sailing barges, the 'Cambria' plying between London, Ipswich and Yarmouth. When forced to earn his living on shore, he has worked as a journalist on sea matters for a number of daily newspapers. He has also written two books on his adventures: Rough and Tumble (Sampson and Low, 1935) and Coasting Barge Master (Edward Arnold 1949).        
He comes of a sea-faring family, his father from Dorset and his mother from Suffolk; went to sea as a boy in a coastal barquentine and as a seaman on coastal barges; a financial crisis at home forced him to work in Fleet Street. Sailed the Atlantic single-handed in a 26-foo cutter; doesn't know why. Shipwrecked on Cocoa Island (off Costa Rica; in the north Pacific; taken off in American schooner and then shipwrecked in her; finally rescued by U.S. Navy and towed to Panama. Then came back to barges; sailed last "bommy barge" for Everards of Greenhithe, and then with his mate Ted Evans sailed the 'Cambria' for Everards,"

As far as singers we have recorded Walter never wrote a song; the nearest thing he came to it was to put a tune to Thomas Hardy's poem, 'The Trampwoman's Tragedy', but as he never sang it to anybody but Pat and I, there was no chance of anybody else taking it up and putting it through the 'traditional sausage machine' so, as far as I'm concerned it cannot be described as 'traditional'.
A number of singers we met did compose songs. Junior Crehan, fiddle player, singer, storyteller (died 1998 aged 90) made a number. To our knowledge only one, 'Lament For Willie Clancy' was taken up by others in his community, and this remained unaltered, so his songs were always referred to here as 'Junior's'.
Duncan Williamson gave us several self-penned songs, but to my knowledge nobody else ever sang them. He was one of a number of people who claimed to have written 'Freeborn Man'. Interestingly (to me) 'Freeborn Man' and 'Shoals of Herring' have been taken up and altered by people they were written about (Travellers and fishermen), whether this qualifies them for the title 'traditional' is, as far as I'm concerned, a moot point. 'Herring' was 'collected' a decade after it was composed, by an American scholar (as 'Shores of Erin'), who described it as 'typical of the songs still to be found among Kerry fishermen'.
We have recorded literally dozens of songs, from Travellers and in West Clare, which must have been made during the lifetimes, or within easy reach of the lives of the singers, but the odd thing is that, except in a few cases, we have been unable to discover the identity of the authors. Two interesting exceptions were a couple of songs, one about a match-made marriage, another concerning a minor incident during the Irish War of Independence (or maybe The Civil War). In both cases we were given descriptions of how the songs were composed; both communally made by a number of people.
Song-making still goes on in Ireland, much of it nowhere near as self-conscious and introspective as that to be found in the UK. The Cap'n will probably be aware of Con 'Fada' O'Driscoll who continues to churn our such magnificent pieces as 'The Spoons Murder', 'The Pool Song' and a recent masterpiece 'Ben Hur', but as popular as these become, they stand little or no chance of becoming traditional as the machinery has been dismantled and that particular factory has been pulled down. Universal literacy and electronic communication have more-or-less guaranteed that new songs come into this world stillborn and the copyright laws have done much to stifle any chance of them entering the 'folk process' and being adapted. Can never see over 200 versions of 'Willie McBride' as is the case with 'Barbara Allen'.
Jim Carroll