As fans in vibrant floral dresses, wide-brimmed cowboy hats and leather boots flaunted their southern-inspired style down Sixth Avenue and into Radio City Music Hall Friday night, the famous New York City venue was transformed into a set fit for Maren Morris’ breezy pop-country twang. The stage was decked out in patches of tall green grass and luminous trees in preparation for the 32-year-old singer-songwriter’s return to the historic venue, after her Christmas show in 2019. Four years prior in 2015, Morris played at the Gramercy Theater; her first show in the city, capacity 650 fans. A short …