The North Bay's growing cadre of community orchestras make classical music accessible to almost everyone who wants to hear it, for an affordable price.

These amateur and semi-professional musicians often rehearse late into the night after a long day at work. In return, they get the chance to perform some of the most thrilling works on the planet. And that's why they do it.

"Having that experience of the full orchestra is really kind of mind-blowing," said Mary Cornett of Rohnert Park, a violinist with the all-volunteer American Philharmonic Sonoma County. "It's quite an adrenaline rush to be part of such a big, complex thing. And it's hard to get."

While groups like the Ukiah Symphony and the Santa Rosa Chamber Orchestra hold weekly rehearsals, the American Philharmonic starts rehearsing just three weeks before each concert set.

That way, orchestra musicians like Cornett, who teaches chemistry at Santa Rosa Junior College and has two children, can take a break between concerts and focus on her life as a chemist and mother. She calls it "musical efficiency."

Chris Krive of Petaluma, principal oboeist with the American Philharmonic, started playing with the ensemble after a long hiatus from music, when he was concentrating on his career as a computer consultant and his family of five kids.

"It was scary to think about going back," said Krive, who was a performance major at Michigan State University. "I thought, 'Can I actually play?'"

But about five years ago, Krive was lured back onstage when there was an oboe opening in the American Philharmonic, now based at Santa Rosa High School.

"It's what I was made for... to communicate the meaning of the music to the audience," Krive said. "You have to bring life to the music, and that takes the right kind of emotions and feelings."

One reason the American Philharmonic can attract high-caliber musicians is that it programs repertoires that would challenge a professional.

"We're playing everything," Krive said, "and a lot of music that I never played before."

That programming has lured players from all over the Bay Area and attracted a new conductor, Costa Rica native Norman Gamboa, who also conducts a professional orchestra in Wyoming.

"The range of the literature is very dynamic," said Nicholas Xenelis, principal clarinetist with the American Philharmonic. "These are the grandiose, big works that require massive numbers of instruments."

Xenelis also leads the Santa Rosa Chamber Orchestra, an all-volunteer group offered by SRJC's Community Education program. The small orchestra counts many loyal members among its ranks.

"I joined in 1981, and some of those people are still there," said Xenelis. "We have a pretty long history."

Violionist Margie Rice has been playing for 27 years with the Ukiah Symphony, where she serves as the concertmistress.

"Our nucleus is small, but we draw form the Bay Area and all of Mendocino County," she said. "When my kids were small, I started teaching, and now it's my profession."

Les Pfutzenreuter of Hopland, who conducts the Ukiah Symphony, launched a new orchestra two years ago at the request of the Raven Performing Arts Center board of directors in Healdsburg.

The Philharmonia Healdsburg draws upon both professional and amateur musicians, paying a small salary that varies, depending on how far people have to drive.

With community orchestras in Napa and Vallejo no longer in operation, the birth of a new ensemble may be regarded as a risky venture. But Pfutzenreuter is optimistic.

"The audience is growing," he said. "With the Santa Rosa Symphony going to the Green Center, we're hoping that we can be the classical music north of Santa Rosa."

Meanwhile, the North Bay's volunteer musicians continue to juggle the demands of Stravinsky and Debussy with their careers in engineering and medicine, teaching and research.

"There are times when I'm tired and don't want to go to rehearsal, but I come out energized," said Cornett. "The non-professionals do not take it for granted. They are choosing to be there."

You can reach Staff Writer Diane Peterson at 521-5287 or diane.peterson@pressdemocrat.com