Any questions about fly fishing? Ask Jason Borger, who has been fly fishing all his life, writing on it since he was 13, and doubled for Brad Pitt when that obsession of his mattered most in Robert Redford’s Academy Award-winning A River Runs Through It. Now Opera Montana is celebrating the 50th anniversary of Norman Maclean’s original spare yet luminous classic, adapted by the librettists Matt Foss and Kelly Rourke, with music by Zach Redler—and once again, Borger’s expertise is proving indispensable. When Ross, who is also directing the production, invited Borger on as a consultant, Borger knew just what to tell him: “Take whatever we did in the film and do the opposite. On stage, you get one shot. It’s all live. It either works or it doesn’t.” Spare yet luminous, Maclean’s lightly retouched personal history circles mothlike around the flame of the narrator’s charismatic, self-destructive kid brother Paul, whose violent early death haunts him to the distant end of his days. As Paul, Brad Pitt’s Big Sky American Apollo set the screen aglow. Now it’s up to the tenor Michael Kuhn to sound the depths of Paul’s enigmas and project, with all the metronomic grace Zen master Borger can help him muster, the epiphany of his most Transcendentalist moments. —Matthew Gurewitsch