By Ken Paulson — Crosby, Stills and Nash offered up a successful template, but the merger of singer-songwriters in a group can have widely varying results. Souther-Hillman-Furay fell short of their promise; Bryndle never took off; the Thorns (Pete Droge, Shawn Mullins and Matthew Sweet) sounded great together, but that’s apparently as far as the harmony went. And then there…
