David Cale in Blue Cowboy, at the Bushwick Starr. Photo: Maria Baranova “There’s a short story by the writer Annie Proulx called ‘Brokeback Mountain,’” the erudite, socially awkward New York writer tells the cowboy he has stumbled into romancing. “I think you should read that.” “Saw the movie,” the cowboy responds. “Was good. Good enough that I don’t think I need to read the story.” The exchange, which David Cale acts out midway through his solo performance Blue Cowboy , triggers a cascade of