Saturday's free mega-concert on will be broadcast live exclusively by Globo in Brazil. Trending on Billboard Shakira is ready to make history in Brazil and deliver one of the most important concerts of her successful career. The Colombian superstar will take the stage on Saturday (May 2) at the iconic Copacabana Beach as the headliner of Todo Mundo No Rio, the massive free event that attracts millions of people to Rio de Janeiro, where icons like Madonna and Lady Gaga have performed in the past. In an emotional open letter published this week by the Brazilian newspaper O Globo — and shared with Billboard in English by her representatives on Wednesday (April 29) — Shakira spoke about what promises to be a historic performance at the iconic Brazilian beach.…