Lady Gaga has officially been announced as the main headliner of "Todo Mundo No Rio," the free concert taking place on May 3rd in Copacabana, at the presso conference for the event. Lady Gaga took to her social media to announce her return to Brazil after more than a decade. It's a great honor to be asked to sing for Rio--for my whole career the fans in Brazil have been part of the lifeblood of the little monsters. I've been dying to come perform for you for years and was heartbroken when I ha