Jim , I have been singing traditional songs for over 40 years, Ihave not lost the abilty to perform them or relive them, the fact that i am a revivalist singer rather than a traditional singer , does not matter if one is judging on musical merit, which is the criteria of most people when they listen to jazz ,classical music or most other forms of music.
I too have an inate understanding of the songs, some of the songs are part of my life i too werar them like a comfortable jacket, as do some other revival singers.
the term revival is meaningless, if one is judging purely on interpretation and style of the music.
example that proves my point Bob Blake, collected by Mike Yates[ who mistakenly thought he was a traditional singer] in fact he was singer who learned songs from books but who had lots of friends who were traditional singers[ yet he sang in a traditional style]. and no one could tell he was not a traditional singer because he bloddy well sonded like one.
its high time all this nonsense about traditional singers being somehow superior [just because they learned orally, and regardless of singing abilty] is done and destroyed.
yes there were some very good traditional singers , there were also some not so good ones, and do you know why, it was because some had musicalty and some didnt, not much different from revival singers really, [it was nothing to do with oral transmission]it was to do with their ability as singers.
even if a traditional singer had agood singer to learn from in anb oral way ,that still does not guarantee that the aforesaid traditional singer might be any good ,he might be not vey musical or even tone deaf.