"a new Opera House"

The new opera house referred to here is the Metropolitan Opera House, which would open in 1883 and within three years supplant the Academy as New York City’s prime opera venue.

It was created by the nouveaux riche (Wharton refers to them in the novel as the 'new people') who had been frozen out of the Academy.

The Metropolitan outlasted the Academy by just over 40 years before, in 1967, it too was demolished.

 

Interior of the Metropolitan Opera House, seen from the rear of the stage, during a concert by pianist Josef Hofmann (1937)
Public DomainInterior of the Metropolitan Opera House, seen from the rear of the stage, during a concert by pianist Josef Hofmann (1937) - Credit: U.S. Information Agency
Metropolitan Opera House (1905)
Public DomainMetropolitan Opera House (1905) - Credit: Detroit Publishing Company