Largest attendance at a classical concert

Largest attendance at a classical concert
Who
New York Philharmonic
Where
United States (New York,Great Lawn, Central Park)
When
An estimated record 800,000 attended a free open-air concert by the New York Philharmonic conducted by Zubin Mehta, on the Great Lawn of Central Park, New York, USA on July 5, 1986, as part of the Statue of Liberty Weekend.