Nearly every city lives with at least one terrible ghost. Dallas has J.F.K., New York the Triangle Shirtwaist Factory Fire. Philadelphia is haunted by MOVE. More than three decades have passed since Philadelphia police bombed the West Philadelphia home of the MOVE collective, setting off a fire that killed 11, destroyed 62 rowhouses, and left the city's conscience to rattle around with no clear path to repose.

The opera stage isn't a likely place for resolution, and We Shall Not Be Moved, premiered Saturday night at the Wilma Theater as part of Opera Philadelphia's O17 festival, doesn't try. In fact, it isn't even about MOVE itself (though it opens with a quick recap of some of the main events).

The piece takes place decades after the MOVE immolation and centers on a group of teens who have fled a violent incident in North Philadelphia to take refuge in an abandoned house in West Philadelphia. It turns out to be one of the Osage Avenue homes rebuilt after the fire — the exact site, in fact, of the MOVE headquarters. Ghosts hang around the house, sometimes dropping notes with messages on the teens, who, we conclude, are their heirs of sorts — to gun violence, injustice, and the tension of wanting to live in a system that has thoroughly debased the value of human life.

The teens are discovered. A police officer named Glenda — sung poignantly by Kristin Chávez — tries to help, but becomes ensnared in their chaotic existence. We Shall Not Be Moved explores the human side behind blunt headlines — the quickness with which police shoot civilians, the question of  "who cares for the brown girl gone missing" — but is at its best when, through minimalist repetition of text and sound, it allows the audience to connect more subtle dots. Across two acts, the human body emerges as a theme: how absurd it is that we all get so hung up on the trappings of our physical manifestation (race, and one character who is "betwixt" genders).

The music is by Daniel Bernard Roumain, the meditative libretto by Marc Bamuthi Joseph, and the genre straddles several musical styles, but is mostly a low-key funk. In some ways, it's a highly polished piece of theater. Pangs echo across the stage through Jorge Cousineau's striking images of Philadelphia street scenes, skies of freedom and ghostly white figures projected onto diaphanous scrims, suggesting the fragile, ephemeral nature of life for these characters. Bill T. Jones is director, choreographer, and dramaturg, setting in motion a handful of ghost dancers to animate the stage. A small ensemble led by conductor Viswa Subbaraman sits far back on the stage behind the action.

Can a piece of music or theater be both great art and political commentary? Of course it can. The problem with We Shall Not Be Moved is that while the libretto can be poetic and pointed, the music is neither — it's more functional than the source of beauty or pain — and so we are left with thinking about this piece mostly for its social-justice mission.

What, exactly, is that mission? The authors take some revealing peeks inside the soul, such as the one near the end when the tables are turned — yes, literally, with a rotating piece of the set — on Glenda the cop, now being grilled by her captor, a 15-year-old girl who goes by the name Un/Sung, played commandingly by Lauren Whitehead. We are told more than once: "The one holding the gun chooses the future of everybody."

This new opera doesn't tell us why MOVE happened — that is, how humans could drop bombs on humans and sit there as the fire burns. But if that's a bleak thought, this opera has a bleaker one: how little has changed since May 13, 1985. Same human wreckage, different day.

We Shall Not Be Moved is performed at the Wilma Theater, Broad and Spruce Streets, Sept. 17, 18, 21, 23 and 24. A few tickets remain for some performances at $75-$100., 215-732-8400.