Chris Stapleton appeared to be one of those overnight storybook sensations: a troubadour who came out of nowhere to become a major star in the autumn of 2015 on the strength of his debut album Traveller. Like most overnight sensations, Stapleton had a long, hard road behind him. He had been laboring behind in the scenes in Nashville for years, leading the progressive bluegrass group the SteelDrivers and working as a professional songwriter, scoring hits with George Strait ("Love's Gonna Make It Alright"), Kenny Chesney ("Never Wanted Nothing More"), Luke Bryan ("Drink a Beer")...