The original queen of pop talks to Vanessa Grigoriadis about inspiration, aging, motherhood and why she refuses to cede controlThe night before the Billboard Music Awards in Las Vegas in May, Madonna was sitting in the arena attached to the MGM Grand hotel, staring at a double of herself. The double, who was standing on the stage many yards away, was younger and looked Asian but wore a similar lace minidress and a wig in Madonna’s current hairstyle, a ’30s movie star’s crimped blond waves.“It’s always the second person with the wig — she wants to see it,” a stage designer said, adding that when she makes a decision, she is definitive.Madonna was observing Madonna to make sure Madonna was doing everything perfectly. Up on the stage set of a funky urban street with lampposts and a tiled bar, the double hit her marks and held a fist up to her mouth like a faux microphone for a rendition of “Medellín,” the on-trend, Latin-inflected song that Madonna would be singing.Madonna looked at a TV and assessed the augmented-reality part of the show, in which four additional virtual Madonnas, one playing an accordion and another dressed like a bride, would materialise…