Florida Georgia Line came out of nowhere in 2012 to become the biggest country group of the new decade. The vehicle for their success was "Cruise," a slick, shimmering ode to the wide-open road that eventually became the biggest country single of all time. After "Cruise" broke through, its life became extended with a remix featuring rapper Nelly. This unexpected collaboration pushed the single all the way to number four on the Hot 100, but at that point it was clear that the appeal of "Cruise" lay in Florida Georgia Line's unabashedly polished pop perspective. Unlike some fell...