Following this week's announcement about the $550 million renovation for David Geffen Hall, the Lincoln Center home of the New York Philharmonic, most of the buzz has centered on the plan's promise to improve the long criticized acoustics of the venue. But buried amid the details was the disappointing answer to a question that mid-century and public art fans have been asking for years: “Orpheus and Apollo,” a hanging sculpture composed of 190 flat sheets of shimmering metal that seemingly floated above the lobby of the concert hall for 50 years, will not return once the lobby is rebuilt.

"It's morally indefensible," said Theodore Grunewald, a prominent preservationist who has over the years fought to save what he considers important relics of modern art and architecture in New York City.

He added: "They didn’t consult the artist’s estate. They didn’t consult the public."

Created by the late American artist Richard Lippold who was known for his abstract wire constructions, the five-ton, 190-foot-long, 39-foot-high sculpture piece was commissioned for the concert hall when it was first built in 1962. Chandelier-like, the installation hung uninterrupted in the grand promenade of what was first known as Philharmonic Hall and later Avery Fisher Hall for decades, despite being tantalizingly within reach of those leaning over the railing of the upper levels. In 2014, it was quietly removed for "maintenance and conservation." After its prolonged disappearance raised questions, Lincoln Center officials said it would not return due to the anticipated renovation. They also did not commit to bringing back the sculpture after the new lobby was completed.

Grunewald, as well as others, have argued that the sculpture was doomed once it was taken down. Lippold himself was said to have warned against ever taking the piece down.

"It’s really tragic because of the complexity of the sculpture. Once you take Humpty Dumpty apart, it’s hard to put it together again," he said.

According to a New York Times story in 2015, the piece was disassembled and put in an art storage facility in New Jersey. At the time, the Times said that relocating the sculpture would be difficult because of its sheer size.

The Associated Press reported that Deborah Borda, the president of the New York Philharmonic, said that the sculpture, which used some 450 steel wires, will not be reinstalled in the lobby "because of current safety standards that impact the wiring."

A spokesperson for Lincoln Center did not immediately respond to a request for further details.

Michele Bogart, an art professor at Stony Brook University who has written extensively about the history of public art in New York City, noted that Lippold's sculpture, with its play of space and light, was an intricate part of the design of the original concert hall. It is meant to evoke two figures: Apollo, the god of music, and Orpheus, the famous musician and poet from Greek mythology who tried to summon his wife Eurydice back from the underworld by singing and playing the lyre.

"It’s to create this celebratory environment to complement what’s going on the theater," Bogart said. "Why take away something like this?"

She bemoaned the loss of the work as part of a more troubling trend in the preservation of midcentury modern architecture.

"In the larger scheme of things, Lincoln Center has been dismantling aspects of its original physical design," she said, adding that the complex itself is "a really important design artifact of early 1960s" that was intended to be a capitalist response to the Soviet Union meant to showcase the country's cultural prowess.

In general, she said modern and avant garde art runs the risk of being disposed.

"It’s not pretty or pleasing in the way people want to be pleased, and the reaction now is to get rid of it," she said. "That to me is a problem."

Even those outside the art world but who had grown up associating the sculpture with Lincoln Center were saddened by the news.

In an email, Eddie Crimmins told Gothamist that he first saw the work as a teenager in 1966. In 2009, he took photos of the sculpture, which to him resembled two birds in flight. For him, the work was an entry to the world of modern art, which he admittedly didn't always like.

"I realized that modern art might not suck," he wrote. "And in some odd way, those sculptures gave me my wings."