CRITICAL MASS | OPINION: Ann Powers goes looking for Joni Mitchell

In the penultimate episode of the third season of HBO's wonderful "Hacks," a relationship comedy about the dynamic between Joan Rivers-style comedian Deborah Vance (Jean Smart) and a Gen-Z writer Ava (Hannah Einbinder), a New Yorker writer with a reputation for eviscerating her subjects, punctuates a profile of Deborah with...