Jim James, the frontman of My Morning Jacket, has lived many lives over the band’s 27-year career. He started as a hopeful young musician, chasing the magic of his musical heroes—while secretly fearing he’d never measure up. Later, he spiraled into heavy drinking and self-doubt, teetering on the edge of leaving the band. But today, Jim is in a much different place. Healthier, more grounded, and...