The 48-25 vote makes them members of the American Federation of Musicians, which covers 80,000 musicians in the United States and Canada.

HYANNIS — The more than 70 musicians who play in the Cape Symphony have voted to unionize five years after a similar effort failed by a narrow margin.

The 48-25 vote makes them members of the American Federation of Musicians, which covers 80,000 musicians in the United States and Canada. The results of the mail-in ballot to the National Labor Relations Board were released Wednesday, said Patrick Hollenbeck, president of the Boston Musicians' Association, the AFM local that covers the Cape and Islands.

"It was clear it was the will of the orchestra," he said. "It was a strong mandate."

In 2011, the National Labor Relations Board, an independent federal agency that protects the right of employees to work together to improve their wages and working conditions, rejected a request by the orchestra to block a vote by musicians to join a union. The NLRB ruled that musicians were employees rather than independent contractors and had the right to collectively bargain.

But the unionization vote failed by a four-or-five-vote margin, Hollenbeck said, and the issue did not resurface until late 2016.

Douglas MacDonald, chairman of the Cape Arts and Entertainment board, said in a statement that the board respected the musicians' vote.

"We have every confidence that our past, direct interactions with the orchestra members were fair and effective and that the relationship between management and the orchestra was constructive," he said in the statement. "We know our colleagues in the symphony share our commitment to enhancing the arts and music community on Cape Cod and we do not expect this recent decision to have any impact on our ongoing work."

The symphony and the Cape Conservatory merged in 2010 to form Cape Arts and Entertainment.

Hollenbeck said union members will now vote on a negotiating committee, which will take a survey of its members to determine which issues to address with the board. Ultimately, the two sides will work toward a collective bargaining agreement, he said.

About half of the symphony's musicians have been covered by a union in past work, Hollenbeck said, and wanted to bring union protections to the Cape.

"They just want to see things evolve down there and they want to be a part of it," he said.

Efforts to reach members of the Cape Symphony's organizing committee were not successful Wednesday.

— Follow Sean F. Driscoll on Twitter: @seanfdriscoll.