(Production photo: Duane Tinkey/Des Moines Metro Opera’s “Billy Goats Gruff”) Father of six, retired bass-baritone John Davies first attempted to write a children’s opera for an unusual reason. “Around 1978,” he remembered in an interview with OperaWire, “it seemed to me that the tobacco industry was advertising to my young children, with the Marlboro Man, Joe Camel, and Virginia Slims {…}