The committee quickly reinstated Mr. Gillinson and agreed to appoint a lawyer to investigate Mr. Perelman’s concerns. But the tumult did not end there. Mr. Perelman is stepping down this week as Carnegie’s chairman after just eight months; Mr. Gillinson remains in charge but under an internal investigation; and Carnegie, the most important concert hall in the nation, if not the world, finds itself facing an unusual public crisis in the midst of a $125 million fund-raising drive.

It is not how the hall expected to be starting an anniversary season, 125 years after opening with Tchaikovsky conducting his “Marche Solennelle.” The conflict — pitting Mr. Perelman, one of the nation’s wealthiest businessmen, against Mr. Gillinson, a former cellist who was knighted in 2005 for his work as managing director of the London Symphony Orchestra — has transfixed the worlds of music and philanthropy. And it has raised anew questions about the proper roles of boards and staffs at nonprofit institutions.

Both sides have remained publicly silent on the issue. Mr. Gillinson issued a statement when Mr. Perelman’s criticisms first surfaced last month saying that he had served Carnegie Hall “to the best of my ability for 10 years.” But Carnegie and Mr. Gillinson will not comment further “while an internal review is ongoing,” said Synneve Carlino, a spokeswoman for the hall, and Mr. Perelman declined to comment as well. But letters to the board, and interviews with people sympathetic to both camps who were granted anonymity to discuss a matter that is under investigation, provided a fuller, but still incomplete, account of the dispute.

The tumult is adding a dose of unexpected, and unsought, drama to the gala performance (featuring the New York Philharmonic and the pianist Evgeny Kissin) and dinner planned for Wednesday. The evening is expected to draw Mr. Gillinson and members of the board, but probably not Mr. Perelman. And many will be thinking about the board meeting scheduled for the next day, when a new chairman is supposed to be selected.

Image Clive Gillinson, the concert hall's executive and artistic director. Credit... Karsten Moran for The New York Times

The appointment of Mr. Perelman, who has a reputation for being aggressive, and even pugnacious, as chairman after Sanford I. Weill stepped down in February surprised some board members. Some figures in the classical music world were alarmed when Mr. Perelman was quoted as saying that he hoped to stage more pop performances at Carnegie, as was done decades ago; he later sought to reassure people that he understood the importance of classical music at Carnegie, and bought a box for the whole season.