'The murder of Leon Klinghoffer will not be forgiven!"

Those words rang through the Metropolitan Opera house Monday in one of several not-unexpected heckling intrusions during The Death of Klinghoffer, John Adams' 1991 opera that, for all its artistic worth, gets the award for being in the wrong place at the wrong time.

During months of claims that the work glorifies terrorism and that the production should be canceled - the Met's HD simulcast in fact bit the dust - The Death of Klinghoffer became a straw man, a target for accusations that often failed to make sense. Outside the Met, amplified speakers declared the event was the second death of Leon Klinghoffer, the wheelchair-bound New Yorker shot by Palestinian hijackers of the cruise ship Achille Lauro and dumped overboard in 1985.

Monday's Met debut was the wildest opening in memory. Though the opera was seen years ago at the Brooklyn Academy of Music, the uproar over this production is unlike any earlier one. Former Mayor Rudy Giuliani, enlisted by protesters as a speaker, was reportedly too nuanced in his objections (he had actually heard the opera) at Monday's rally. Some protested in rented wheelchairs, barely visible behind the riot barriers.

Opera-goers had to show tickets to the police just to enter Lincoln Center plaza (and those with "will call" tickets had lots of explaining to do). At intermission, tickets had to be reexamined. The corps of natty Met ushers appeared to have been augmented with burly bar-bouncer types who prowled the aisles during the performance. One man was arrested for disorderly conduct. Another recited the Kaddish loudly during intermission, followed by street language.

The pro-opera sentiment was apparent - extravagant cheers for conductor David Robertson, an even louder ovation at the end of the opera when composer Adams appeared. In the new Tom Morris production (already seen at the English National Opera), the portrayals of Leon and Merilyn Klinghoffer couldn't have been more noble. Veteran baritone Alan Opie projected indignant stubbornness at gunpoint, and mezzo-soprano Michaela Martens sang with great eloquence when confronting the ship's captain (somewhat blandly sung by Paulo Szot) for being too ready to negotiate with the terrorists.

In a story told as a series of flashbacks by multiple narrators, the production was a model of clarity in showing whose memory was at work. It avoided much abstraction in flashback accounts of the hijacking and gave serious individual attention to the range of humanity the opera presents. Scenically, computerized graphics showed desert scenery, watery expanses, and the Mediterranean sun growing more intense as terrorists screw up their rage to murder Klinghoffer.

And the problem is? Clearly, last summer's war in Gaza and the rise of brutal ISIS in Iraq and Syria ambushed the Met production, in the planning for years. The larger public presumably is unaware of how opera slots work at the Met, or that the timing with recent events could not have been less intentional. But those in a blind rage tend not to take in that sort of information.

The larger picture, though, shows what happens when an artistic vocabulary is scrutinized out of context by hostile parties, yielding all manner of unintended meanings. The root of the opera's troubles in 1991 emanates from a scene that was hugely misread and cut early on after the premiere in Brussels. It's a worthy case in point.

The original prologue was a triptych, first with Palestinians displaced by the creation of Israel in 1948, then European Jews arriving, many of them Holocaust survivors. In between was the excised scene, which showed a middle-class American Jewish family in a mid-'80s living room, having coffee and conversing aggressively. The scene functioned to show how far removed Americans were from the imminent hijacking. But it became offensive perhaps due to the staging, which had the physically animated trademark of the original director, Peter Sellars, but, to many eyes, suggested mockery.

The opera goes on to resolutely defy rules of well-made drama, intentionally leaving itself open to a variety of interpretations, making it a sitting duck for those looking to find fault. The ultimate message reaches beyond Israel/Palestine issues, showing how pointless the event had been - the Palestinians wanted prisoners freed and got nothing. In the course of their failure, the sole victim was an utterly innocent man.

Now, The Death of Klinghoffer is taking bullets, even though the piece itself assures that Klinghoffer's death will not be forgotten - as long as other opera companies aren't frightened away from producing it. It was heard in Philadelphia in a Curtis Institute of Music production in 2005, but the Los Angeles and Glyndebourne companies opted out of the original production.

In discussions of the opera, the last question is usually, "How good is it?" Under present circumstances, it's hard to stand back and say with confidence. The choruses alone eclipse Adams' previous Nixon in China. It's also possible that Adams surpassed himself in later works, such as El Nino and Doctor Atomic. Perhaps the most ringing vote of confidence for Klinghoffer, though, comes from the protesters. People don't get angry over fluff.

dstearns@phillynews.com.