Top 15 largest concert crowds:

1. Queen, Sydney [2,000,273]
2. Monsters Of Rock festival, Moscow headlined by AC/DC, Tushino Airfield [1,600,000+] (**)
3. Peace without Border Concert, (2nd edition) Havana sep 20, 2009 [1,500,000] (***
4. Rolling Stones Feb 2006 at Copacabana Beach [1,500,000]
5. Garth Brooks in Central Park [980,000] (****)
6. New York Philharmonic in Central Park [800,000]
7. Steve Wozniak's 1983 US Festival [670,000]
8. Summer Jam at Watkins Glen [600,000+]
9. Isle of Wight Festival [600,000]
10. Tokio Hotel in Paris, France [500,000+]
11. Simon & Garfunkel in Central Park [500,000]
12. Genesis, Turn It on Again: The Tour in Rome [500,000]
    
13. Toronto SARS Benefit [450,000]
14. Woodstock 1969 [400,00]
15. Rock in Rio 1985 headlined by Queen and Iron Maiden [300,000]

Jean-Michel Jarre performed 4 concerts over 1,000,000 people:

1979 - Guinness Book of Records entry for the biggest concert ever (La Concorde):[1,000,000]
1987 - New Guinness Book of Records entry for the biggest concert ever (Rendez-Vous Houston):[1,500,000]
1990 - New Guinness Book of Records entry for the biggest concert ever (Paris La Defense: A City in Concert): [2,000,000]
1997 - New Guinness Book of Records entry for the biggest concert ever with 3.5 million watching at Moscow's 850th anniversary






(*) The first item on the list seems to be genuine, making Rod Stewart's Copacabana gig the biggest ever concert, with 3.5 million spectators.

Stewart was inducted into the Rock and Roll Hall of Fame in 1994. On 31st December on the same year he played in front on 3.5 million people on Copacabana Beach in Rio. This became and still is the largest audience for a gig ever. It has been noted, however, that it was also New Year's Eve.

(**) September 28th 1991, Metallica appeared as Special guests of Monsters Of Rock tour in Moscow, Tushino Airfield. Bands included AC/DC, Metallica, E.S.T., Black Crowes, Pantera. Legend has it that the President of the Soviet Union Mikhail Gorbachev personally invited the band to play at the concert.

(***) Peace without Border Concert held at Revolution Square, in Havana, featured 15 artists from six countries, including Colombian rocker Juanes, Puerto Rican tropical music star Olga Tañon, Spanish pop singer Miguel Bose, plus Cuban singer song-writter Silvio Rodriguez, hip-hop trio Orishas, Van Van orchestra and others.

(****) In May of 1998, the New York Fire Department officially announced the final attendee numbers for Garth Brooks in Central park at 980,000 people.