The Elton John biopic “Rocketman” tells the amazing story of the life and career of the legendary British musician. In the movie, Elton John is portrayed by Taron Egerton. From how to sing to how to play piano to how to move around on stage, there was a lot Egerton had to get right. We spoke with Michael L. Roberts, the movie’s pianist and vocal coach, about how he helped Egerton train for the role.