Conklin made his Glimmerglass debut shortly after Glimmerglass moved from a high-school auditorium to a purpose-built opera house, with productions of “Fidelio” (directed by Jonathan Miller) and “Il re pastore” (directed by Mark Lamos). According to a press release, in the years that followed, John worked closely with General Director Paul Kellogg to meet the challenge—and opportunity—of the new theater and the international attention it garnered.…