There's also the occasional surprise...

John Pizzarelli, though not possessing a voice that most would associate with his particular brand of jazz and standards, nonetheless make those standards, just as Art Theime says, "accessible".

James Taylor is nothing if not a vehicle for making his verse accessible.

And there are a few whose delivery is so idiosyncratic that it's hard to imagine anyone covering their material with nearly the same effect -- folks like Pierce Pettis, or, if you were to go back thirty years in pop -- Cat Stevens or Jim Croce.

Then there are those wonderful deliverers of their own material that makes their writing shine as if from a different facet, though others have covered their material more "ably". Folks like Dave Mallett or Bob Franke.

interesting thread.