I dunno about the settings. I knee-jerk to agree with you about Frank Sinatra and Nelson Riddle. But what do I do about The Weavers with Gordon Jenkins? Or The Norman Luboff Choir? They sure had an influence on me when I was a kid. I figure they're all bridges. Just as the Kingston Trio leads to Frank Profitt and Peter, Paul and Mary lead to Rev. Gary Davis.
And some of the songs of Earl Robinson's and Yip Harburg's that moved into the folk idiom. Did you know that "Free and Equal Blues" was supposed to be the opening number in "Finian's Rainbow"?
If you listen to the cuts on "Songs For Political Action", it's all so unclear. Maybe Pete's "All Mixed Up" should really be our theme. I guess I just go by my gut.
My problem with most contemporary "folksingers" is that they've never heard traditional music. Many of them are third or fourth generation now and "roots" to them means Bob Dylan or Paul Simon.
I'm sputtering out on my soapbox too.