During its opening weekend, more than 200,000 fans turned out to see Katy Perry, Elton John, Rihanna and the Red Hot Chili Peppers among others.
Organizers say all 700,000 tickets for the festival have been sold.
The festival runs until Sunday.
The festival began in Rio de Janeiro in January 1985. The military dictatorship that had governed Brazil for two decades had just ended, and 1.4 million people showed up to celebrate their newfound freedom at a concert that brought international attractions like Queen and AC/DC to Brazil for the first time.
The Associated Press contributed to this report.