Madonna's biggest-ever concert transforms Rio beach into a massive dance floor

RIO DE JANEIRO — Madonna put on a free concert on Copacabana beach Saturday night, turning Rio de Janeiro's vast stretch of sand into an enormous dance floor teeming with a multitude of her fans. It was the last show of The Celebration Tour, her first retrospective, which kicked off in October in London. The "Queen of Pop" began the show with her 1998 hit Nothing Really Matters. Huge cheers rose from the buzzing, tightly packed crowd, pressed up against the barriers. Others held house parties...