It's interesting how people have interpreted the original question. For me, the posts that have nailed their message best have been the ones that addressed the term "traditional" as just that; those posts that explicitly used the term "folk" where Cap'n had written "traditional" may have addressed other issues but not the one I thought he was interested in.

I was listening to a radio program the other day which discussed a piece of (what these days would be called 'ethnography') description of Irish traditional music. The description was written in the 11th century and mentioned the virtuosity and speed of the tunes played by the assembled harpists. My initial reaction was "nothing much has changed in a millenium" but I then got to thinking about the enormity of the technical improvements to instruments from the 17th to the 19th centuries. It's quite likely that those periods saw concomitant increases in virtuosity, as the improved instruments allowed.

But I suspect that players in the 19th century who had excellent skills but not much in the way of feeling would be just as limitied in their abilities to communicate as players in the 21st. And John Carger's programs on singers with more than a little renown and extreme skills (limited as it might be in relevance to this discussion) demonstrates enormous changes in singing styles over only the period we've been able to record them.