Pop Mart tease

POPULAR MUSIC, AS VIEWED BY THE UNPOPULAR: Not so loud—we're still a little green around the gills from last night's post-work "just one cocktail." Anyhoo, Capitol's Katy Perry holds onto #1 at Pop radio, Lava/Republic's Lorde is nipping at her heels, Columbia's Pharrell is Greatest Gainer and Warner Bros.' Jason Derulo keeps up the momentum. And that's just for starters. For more on what's happening at Top 40, pour yourself a stiff glass of Pop Mart. (2/26p)