Jay-Z headlining the Global Citizen Festival was always going to be a major drawcard. So too, the prospect of seeing No Doubt together again on stage, joined for a track by Sting. Adding Carrie Underwood, The Roots and Tiesto to the mix made Saturday’s line-up appealing enough to take on the Global Poverty Project’s initiatives to win tickets to their concert in Central Park. Beyond, of course, the aim itself of ending extreme poverty by 2030. It made sense that Jay would have started his set with Empire State of Mind – as he did, after opening with a mash of Gil Scott-Heron’s NY You’re Bringing Me Down,  Billy Joel’s New York…