An effort to raise money for entertainment workers hurt by the coronavirus pandemic has collapsed because of a dispute between a major charity and a labor union representing musicians.

The charity, Broadway Cares/Equity Fights AIDS, had planned an online fund-raiser on Monday at which it would stream a concert, recorded in November, that celebrated the 25th anniversary of Disney on Broadway. The concert, backed by 15 musicians, was also a fund-raiser, which brought in $570,426 for Broadway Cares.

Two major labor unions, Actors’ Equity Association and SAG-AFTRA, agreed to allow the streaming of the concert without fees, but the American Federation of Musicians, which has been focused on winning greater compensation for streamed content, did not.

“Members of the American Federation of Musicians are suffering from the sudden cancellation of all work as a result of the Coronavirus outbreak,” the union’s international president, Ray Hair, said by email. “During the height of this crisis, Disney Theatrical has come to us asking to stream media content without payment to the musicians involved in the production. Especially now, with zero employment in the entertainment sector, the content producers should care enough about the welfare of those who originally performed the show to see to it that they are fairly compensated when their work is recorded and streamed throughout the world.”

Broadway Cares, which has been raising money for a Covid-19 emergency assistance fund, was clearly frustrated.

“I understand being told no,” Tom Viola, the organization’s executive director, said in a statement. “When that happens — and it does — I can usually see why or understand the extenuating circumstances. It never feels simply meanspirited. This was different and the result, particularly now, is heartbreaking.”

Disney, which has raised nearly $20 million for Broadway Cares over the last quarter-century, was similarly unhappy. “Disney wholeheartedly supported the request from Broadway Cares/Equity Fights AIDS to AFM to waive fees for this fund-raiser, just as many unions and guilds had happily agreed to do,” Disney Theatrical Productions said in a statement. “It’s disappointing that in this case, due to AFM’s decision, much-needed funds will not be raised. We are fiercely proud to be advocates for Broadway Cares and will continue to be, especially at a time like this.”

Early Sunday, after this story was published, the 15 musicians who performed at the concert, joined by the president of their union local, released a statement saying that Mr. Hair had not consulted them, and that they wanted him to allow the streaming of the concert.

“We as an orchestra are happy to forgo any payment for the streaming of this charitable event,” they said. “Now more than ever it is essential to join with the other members of the arts community to help those in need.”

Adam Krauthamer, the president of the union’s Local 802, which represents musicians in the New York region, released his own statement that said, “I am disappointed by AFM President Ray Hair’s statements and his misguided decision.” He added, “During this unprecedented time we all must band together and this was a missed opportunity by Ray Hair, one that he alone can fix.”

Efforts to slow the spread of the virus have idled millions of people, and those working in the arts have been hard hit, as live performances have ceased, museums have closed, and work on film and television shows has been halted.

Many nonprofit and commercial arts institutions, including Disney Theatrical Productions, have furloughed employees in the face of evaporated revenue.

At the same time, many entertainers, isolated in their homes, have been participating without payment in online efforts to raise money for charities seeking to help those whose health or finances have been harmed by the pandemic.

The failed negotiations between Broadway Cares and the musicians’ union unfolded within the last few days, and the tone from the union was harsh.

“When you treat musicians as if they were slaves, you reap the consequences,” Hair said to a Disney executive in an email. At another point, he wrote: “We are in a zero employment situation. I am waiving nothing. That’s final. You should want to pay the musicians, who have no income during this crisis.”

Disney spent around $200,000 to produce the concert in the fall, and paid the musicians who performed. The company said the upcoming streaming fund-raiser was not a Disney event, but a Broadway Cares event, and that it was the charity seeking a waiver.

“They are trying to raise money to help your members and the entire community during this crisis,” Scott Kardel, the Disney Theatrical labor relations director, wrote to Hair. “Your decision means the fund-raising event will be canceled. It’s your decision but it seems a harsh and punitive one to your members and the larger community.”

Broadway Cares argued that it could not afford to pay the musicians for an already recorded concert without also paying the other unions. It noted that it had already given $50,000 this year to musicians’ assistance programs, and offered to give another $25,000 to a musicians’ emergency fund, which Viola said would be more than the value of the payment Hair was seeking. But Hair refused that offer, writing, “I do not support and will not agree to your demand for gratis services during the current crisis.”

Broadway Cares then decided it had no choice but to cancel the fund-raiser, which would have been hosted by Ryan McCartan, with live interviews woven into the streamed concert.

The original concert, performed at the New Amsterdam Theater on Nov. 4, featured songs from Disney shows including “Beauty and the Beast,” “The Lion King” and “Newsies,” as well as some lesser-known titles. (Anyone remember “King David”?) It was introduced by Whoopi Goldberg and performed by a variety of Broadway stars, including Christian Borle, Norm Lewis, Ashley Park and Sherie Rene Scott.