In a quote that is a music PR agent’s dream—and appropriately sprawled all across his printed bio and website—England’s esteemed Mojo magazine once dubbed Jason Ringenberg “The Godfather of Americana.

Guest Porter Wagoner, left, and co-host Tex Ritter, center, of WSM-Radio’s “Opry Star Spotlight” show, listen as co-host Grant Turner gives a station identification on June 22, 1965. J.T ...