Thomas Rhett scored his first No. one hit in 2013 with “It Goes Like This,” introducing a sound that mixed the southern swagger of county music with pop hooks, R&B grooves, soulful strut, and the anything-goes attitude of rock. During the years since he’s become a husband. A father, too. And, thanks to eight chart-topping singles, a headliner of massive arenas. It’s funny how life can change so much in such a short period of time.