Decked in a hoodie, cargo pants and coveted sneakers, a slimmed-down and clean-shaven Ed Sheeran stands surrounded by bookshelves and a host of world-class musicians. He’s flanked by music director to the stars, Adam Blackstone, who assembled the band and handled bass guitar duties. After opening this Tiny Desk (home) concert with his latest single, “Shivers,” Sheeran introduces himself and proceeds with more hits, new tunes, and a surprise throwback.