Local 802, the New York musicians' union, which is bitterly opposed to the use of the machine to replace live musicians, had planned protests outside CAMI Hall.

"We are pleased that the Opera Company of Brooklyn and [Sinfonia creator] Realtime's latest attempt to kill live music has been thwarted by CAMI Hall's commitment to live music and 802's ongoing effort to keep music live," said union president David Lennon in a statement.

Meetze said that the demonstration would be moved to the home of an executive of Realtime Music Solutions, which builds and leases the machine. The opera company had contacted audience members individually with the new location, he said, rather than releasing it publicly and giving the union a chance to organize a new protest.

"We're looking forward to developing opera tonight and bringing opera to the masses," he said. "It's not about taking people's jobs, it's about increasing the reach of the art."

The OCB said last summer that it would use the electronic device in place of musicians for a production of The Magic Flute. After protests from Local 802, opera stars Deborah Voigt and Marilyn Horne resigned from the company's board. Months later, the company signed a contract with the union agreeing not to use the machine‹but later claimed that it had been forced into the deal.

The company recently declared that it would use the device in the 2005 season despite the contract. Meetze said last night that it would be used to complement a chamber orchestra for performances in August 2005.

"There is a niche that needs to be filled. We want to make opera affordable for people and accessible," he said.

The Sinfonia uses a series of recorded samples to simulate an orchestral performance. According to Realtime, the machine allows a live performer to control tempo and other subtleties.