For me, the singing of (folk) songs is a matter of trust. For the duration of the song an audience will be asked to listen while the singer communicate a bundle of emotions, ideas, experiences... whatever. In order for the song to work (to my satisfaction) they are asked to believe what the singer is singing/saying, or, at the very least, believe that the singer believes it. If the song is beyond logical acceptance, the listener should be able to suspend their belief for its duration, otherwise it becomes an exercise in technique. Personally, I can't see how this can happen if the language the singer uses is far removed from the way he or she normally speaks, often so far as to sound ridiculous.
I wonder how Americans feel about British singers putting on mock-Southern accents, or East Anglians when somebody from the Smoke does their ooo-aar bit, or an Abedonian listening to a Brummie trying to sound as if he had just come in straight from the bothy.
I can remember my own feelings in the sixties when we Liverpudlians were treated to songs by 'scousers' hailing from anywhere from Scapa Flow to the Isle of Wight - somewhat amused, to say the least. Here in Ireland the practice is occasionally referred to as 'Gobshite Oirish'.
Years ago we became involved (slightly) in the storytelling scene, when we took a few of the traditional storytellers we were recording around to some of the sessions. The contrast between, say Londoners desperately trying to sound as if they had osmosised their stories beside a smouldering turf fire while sitting on their shawl-clad mammie's laps, and Traveller Mikeen McCarthy quietly telling his fantastic tales in his natural Kerry accent, was stunning.
The one bright spark among the revival storytellers was a young West Indian man who told tales from all over the world in his own rich way of speaking.
For me the storytelling movement eventually foundered on the rocks of its own tweeness, and accent played a major part in that.
Jim Carroll