An orchestra without a conductor performed at Carnegie Hall on Tuesday night, and it wasn't due to illness or foiled travel plans. For more than 35 years, the Orpheus Chamber Orchestra has made music without a maestro on purpose.

"With a conductor, you're a cog in the wheel. Your role is passive," a violist entering his 30th season with Orpheus, Nardo Poy, said.

"Here it's about taking ideas from everyone. Any member can stop rehearsal at any point," Mr. Poy, who also serves on the board of trustees, said.

The orchestra's season-opening concert with soloist Yefim Bronfman showed Orpheus at its most ambitious, taking on the Brahms Piano Concerto No. 1. The musicians loved the challenge.

"There was energy in every moment," a violinist, Louise Owen, said.

"I didn't want it to end," another violinist, Carmit Zori, said.

The piece was well received, too. "Who needs a conductor? Think of all the money you save," one audience member quipped from his box seat.

"That was amazing. I could barely sit still," another fan said.

There is a method to how the orchestra works. For each piece, members elect a "core" of musicians who outline its interpretation and a rehearsal plan. The orchestra elects three of its members to serve as artistic directors, guiding the programming and personnel. A member of the orchestra also serves as a senior director.

The soloist Mr. Bronfman said he was initially skeptical, but during rehearsals was quickly impressed with the results.

"The challenge for the musicians is to catch on to the style of the soloist," one of the artistic directors, Christof Huebner, a violist, said. Because the musicians depend on one another, they listen more closely and play better than they might with a conductor, several members of the orchestra said. They also wind up taking more risks.

Board member Kim Bleimann, who played the French horn in his childhood, would like to see the orchestra sell out Carnegie Hall. The series, which this year is named after him, continues on December 8, February 2, April 1, and May 10. With the number of guests for its opening night more than doubling over a two-year period, the Orpheus Chamber Orchestra has become a big deal. This success reflects a new level of professionalism in the administration, which includes the creation of a new group, Young Orpheus, for supporters in their 20s and 30s.

"Our job is to support the musicians," the chairman of Orpheus's board, Richard Lannamann, said.

In addition to its Carnegie Hall engagements, the orchestra will go on a two-week tour of Asia in 2008. It has also issued more than 70 recordings.

agordon@nysun.com