Descendants of Henry Clay Frick are at war over an expansion plan that would see the destruction of the Frick Museum’s famed Music Room to make way for a larger auditorium and a cafe.

Since 1938, the intimate oval-shaped room designed by John Russell Pope has hosted performances by the world’s top musicians, hailed by a top music critic as “the closest thing to a 19th-century music salon this city has to offer.”

But the board of the Frick is pushing for a major expansion and renovation of the Fifth Avenue building, originally a 1914 Gilded Age mansion, which would see the music room demolished to install a large modern auditorium, cafeteria, bookshop and administrative offices.

There are four descendants of Frick on the board supporting the expansion plan, most notably Helen Clay Chace, one of his great-granddaughters who is now president emirata.

But fellow great-granddaughter, and Frick family historian, Martha Frick Symington Sanger has joined the opposition fighting to save the music room. She said, “The opposition and I are not against improving the infrastructure at the Frick, it is the way they are going about it. It is a travesty.”

“By removing the music room, a one-of-a-kind marvelous room and putting in a very large special exhibition gallery, they will increase the crowds and the noise and chatter, this will also disrupt the serenity that everybody loves at the Frick. It will disrupt the garden court where people come to meditate.”

“This is a real violation of Henry Clay’s Frick’s gift to the public. It is just ruinous, they could easily put this new development underground. The new development will dwarf the original building.”

“The board is failing in its duty to protect a landmark resource. The music room in the Frick is 80 years old, and clearly a cultural and historic resource. It is like taking a wrecking ball to the Taj Mahal.”

As the fate of the music room rests on a decision to be made by the city’s Board of Standards and Appeals at a meeting Tuesday, Symington Sanger believes forces and management at the Frick and on the board of trustees, including Blackstone billionaire Stephen Schwarzman, who has donated millions to the institution, are pushing the development plan for their own glory.

She said, “There are very ambitious people involved … They could develop underground and save the music room but people like this like monuments to themselves.”

However, a spokesperson for Schwarzman and Blackstone said, “This is false. The claim that Steve is the driver or ‘chief proponent’ of the renovation is a fabrication meant to manufacture a false controversy. While the full board has approved this long-standing plan, it was designed, implemented, and executed by the museum’s professional management team…The building will also not be named for him.”

A rep for the Frick added, “This measured plan was conceived by the professional museum and library staff in concert with the Board of Trustees to address the Frick’s long-standing programmatic needs. Having the full support of the Board, the project increases gallery space for the display of art, adds dedicated spaces for the Frick’s education programs, provides for modern conservation facilities, and improves accessibility and visitor amenities.”

“The project will not aesthetically alter the ground floor galleries and will open to the public, for the first time, a suite of rooms on the second floor of the former Frick residence. Critically, this plan preserves for visitors the intimacy that so earmarks ‘The Frick Experience.’”

“Over the past two years, the public has had ample opportunity to comment on the project before the Landmarks Preservation Commission and the Board of Standards and Appeals. The process has been public, rigorous, and transparent throughout.”