Saw a TV program the other night on Frank Harte, an (or the, if you know of him) unaccompanied traditional singer par excellence . The only accompanist he tolerates is one Donal Lunny because "he accompanies the singer in such a way that he still feels unaccompanied!". I think he meant it as a compliment! Apart from the flexibility of time required, he clearly felt that the use of counter melody was a vital part of how it worked.

Just a thought.

Regards