“Every time I get onstage,” Atmosphere's Sean “Slug” Daley told last night's Webster Hall audience, “I’m gonna shit, literally.” And yet he showed no sign of nerves — or defecation! Slug even brought a little touch of summertime to a dreary Sunday with “Sunshine,” while DJ Ant attended to the turntables, cigarette in mouth. Slug later noticed that some of the crowd seemed to have dodged the club's 16-year-old age restriction: “Every year we go out and I feel older and older,” he said, a touch morose. But he then introduced tracks from his positive new album, When Life Gives You Lemons, You Paint That Shit Gold. “When I heard the show got sold out, I got really fucking nervous,” Slug said. “That’s a lot of people.” And yet he got through that shit just fine. —Randi Eichenbaum