“A Star Is Born” is very much a product of our times. Jackson Maine’s problems date back to a wretched childhood, guaranteeing our pity and love, whereas Fredric March and James Mason gave the hero a nasty and dangerous edge. Cooper’s camera crowds the characters, getting in their faces, and the dialogue is determinedly foul with oaths: “If you don’t dig deep into your fucking soul, you won’t have legs.” What? In striving to make the whole thing rough and rooted, Cooper slakes our need for the apparently authentic, and yet the story he tells, with its sudden shock of fame, is little more than a fairy tale. The result is pure Saturday-night moviegoing: it gives you one hell of a wallop, then you wake up on Sunday morning without a scratch.