Madonna ended her career with a free show at Copacabana Beach in Rio de Janeiro . . . and 1.6 MILLION people showed up.
The Rolling Stones "only" got 1.2 million fans when they played there in 2006.
But Rod Stewart's gig there in 1994 was the biggest free concert in HISTORY, with a crowd of FOUR MILLION. Of course, there was also a big New Year's celebration going on at the time.