“There are moments in a rock star’s life that define who he is and how people perceive him as he ascends into the heavens,” John Reid (Richard Madden) tells a young Elton John (Taron Egerton) halfway into “Rocketman.” It’s a corny line, but also an effective one — dually for Elton, who’s immediately seduced, and … Continue reading ‘Rocketman’: Taron Egerton Anchors Dexter Fletcher’s Flashy Elton John Biopic [Cannes Review]