This is all very interesting, but what David is saying in his original post is that he things that the classical music he listens to on the radio already has too much dynamic variance in it (!) - and he's glad that, in his opinion, folk music has little dynamic variance.

My answer is that I believe David to be wrong in his contention that folk music makes relatively use of dynamics. Whatever the distortions and alterations caused by recording may be - and, yes, they can be manifold - performers of traditional music do make use of dynamic variation. Perhaps it all boils down to range in the end - there are obviously huge differences of dynamic range between a solo performer and a symphony orchestra - which may give David the impression that folk singers/musicians are somehow different.