New York’s Metropolitan Opera is gearing up for its most controversial premier in decades.

A large street protest including, apparently, former mayor of New York Rudolph Giuliani descended on the opera house today as it prepares for its opening of John Adam’s 1991 opera, The Death of Klinghoffer.

The opera, which delves into the 1985 hijacking of the Achille Lauro cruise ship by Palestine Liberation Front militants, and the murder of a disabled Jewish American passenger, Leon Klinghoffer, is considered a masterpiece by many music critics, but anti-Semitic by others. Protesters believe that because the opera gives voice to the grievances of the hijackers, it justifies their actions. The Met has received threats, though the opera’s creators, and the Anti-Defamation League, dispute charges of anti-Semitism.

Giuliani said in a phone interview to the New York Times, “It [the opera] didn’t tell the true story; it created for history a myth, and contributed to a sense of moral equivalency—that we should treat both sides the same.” Although Giuliani is not calling for the opera to be canceled or banned, he goes on to say, “there shouldn’t be any threats here, this is a historical, sociological, and artistic issue–not some issue of violence.”

Protests were initially lead by several smaller Jewish groups and conservative religious organizations. In order to cool things down, the Met agreed to a compromise with the Anti-Defamation League, in which the opera house would drop its plans to show the production in cinemas around the world, but would still follow through with its New York schedule.

This is not the first time religious leaders have protested the Met. In 1952, the venue was picketed by Roman Catholic leaders who claimed that the company’s production of Verdi’s Don Carlo made a mockery of religion.