The Glimmerglass Opera is much like the proverbial stone tossed into a pond: The ripples it makes radiate outward long after the stone has dropped from sight.

Founded in Cooperstown in 1975, Glimmerglass mounts a summer festival season that runs no more than eight weeks a year - June 30 through Aug. 23 in 2005 - but the company's influence in the opera world is felt long after the Alice Busch Opera Theater in Springfield Center has been shuttered for the winter.

People who have started careers there over the last three decades will be working onstage, backstage and in production shops and company offices through the coming months (and years), and they'll be doing their jobs all over the country.

Mezzo-soprano Sandra Piques Eddy, who sings Dorabella in tonight's (6/30) season opener, Mozart's "Cosi fan tutte," will return to the Metropolitan Opera this season to sing Cherubino in Mozart's "Le Nozze di Figaro" and Rosette in Massenet's "Manon." Now a Glimmerglass guest artist, she first came to Springfield Center five years ago to be part of the company's Young American Artists Program.

During the summer of 2000, Piques Eddy sang a page in Richard Strauss's "Salome" and was a chorister in Handel's "Acis and Galatea," and she would go on to sing Meg, a leading role in Mark Adamo's "Little Women" in 2002. But she made enough of an impression during her debut season to catch the eye of someone from the Met, which promptly offered her a contract to sing a servant in Strauss's "Die Frau ohne Schatten."

The young mezzo has returned to the Met every season since then, singing bigger and bigger roles each time around, and she has appeared at other major U.S. companies as well.

"With every opportunity that I've had - it's like those seven degrees of separation - I can find how it all comes back to Glimmerglass," she says. "My Met contract came from Glimmerglass. I've sung at the Spoleto Festival and in L.A., which came from the Met which came from Glimmerglass. My singing at the New York City Opera and the Florida Grand Opera came directly from Glimmerglass. It's either that somebody heard me here or maybe I made a connection with a conductor or director here who wanted me to go into a production they were working on somewhere else."

Sarah Coburn, the soprano singing the title role in tomorrow (7/1) night's "Lucie de Lammermoor," tells much the same story, except in her case the Glimmerglass ripple effect began working even before she got to town.

"In December 2001, I did an audition for the Glimmerglass young artists program and was offered the role of Constance in Poulenc's 'Dialogues of the Carmelites,' she recalls. "But between the audition and my coming here, I made my professional debut in Miami at the Florida Grand Opera as Norina in Donizetti's 'Don Pasquale.'"

This wasn't a matter of chance: Glimmerglass music director Stewart Robertson holds the same post in Miami, and one of the goals of the young-artists program is to showcase participants so they'll get other offers. This "showcase" was just a little closer to home than some.

And Coburn came back last season as a guest artist to sing the title role in Gilbert & Sullivan's "Patience," which was under the musical direction of Andrew Bisantz, yet another artist who has been building a career at Glimmerglass. He came to town in 2001 as an assistant conductor on Chabrier's "L'Etoile" and Britten's "The Rape of Lucretia" and the following year did the same chores on "Little Women" and "Dialogues of the Carmelites."

Last season he was one his own with "Patience" and will be doing the same in 2005. "There is nothing like being at Glimmerglass because everybody who's important in opera sees everything here now. The company has reached such a stature in the operatic world - in America, particularly, but increasingly internationally - that I've already had discussions with people at various other places of possibilities in the near future."

"Exposure is probably the main thing a young artist gets out of Glimmerglass," says Nicholas Russell, who heads up the young-artists program. "The company's proximity to New York City allows the critical coverage to be wide; it also allows artist managers, primarily based in New York, to come here for performances and to hear members of the program in audition."

And Glimmerglass's clout is just as strong backstage as it is onstage. Master carpenter David Benetello is building the scenery for the double bill of operas that opens July 16 - Massenet's "Le Portrait de Manon" and "Poulenc's "La Voix Humaine." Stewart Robertson will conduct the Massenet opera; Andrew Bisantz will be on the podium for the Poulenc. Usually, Glimmerglass sets are built by outside scenic shops, but this time the work is being done in-house.

Benetello had to leave his winter job early to get started on the project, but it wasn't a problem. Many of his colleagues at Baltimore's Center Stage, where he's one of five stage carpenters, have spent their summers working in Springfield Center, he says, and they were more than sympathetic.

"If you apply to some theater for a job, there's a good chance someone in the upper management has worked here in the past," he says, "so they're comfortable calling our technical director, Abby Rodd, and asking for a reference. Working here opens doors across the country."

Of course, it would be ironic if Glimmerglass developed talent for every other opera company and not its own. But that's hardly the case. The company seems every bit as capable at finding people to fill its jobs and keeping those folks when they find them. Abby Rodd began working at Glimmerglass 14 years ago, when she was a teen-ager. The Cooperstown High School graduate started out pushing around props and furniture, as she puts it. She was on the "run crew" then, and so was her older sister.

Rodd was interested in theater, so during the summers she worked at Glimmerglass and, during the school year, studied technical theater at SUNY-Oswego. After college, she worked winters at the Long Wharf Theater in New Haven, Conn., and came back home each summer. Last September, the company named her its full-time, year-round technical director. She supervises every aspect of the Glimmerglass stage and the physical productions that fill it.

"This company has historically given people a chance to move up and prove themselves," she says. "I had never been a technical director before. I had been an assistant technical director, but they knew that I was invested in the company and were willing to give me a chance at it.

"They do the same thing for a lot of people on the production staff, and I think it keeps people sticking around here because they see that they can get the chance to move up in the world. We get lots of people returning every year because of that."

Managing director Jeryl Dropp has been at Glimmerglass nearly twenty years; that has been the easy part. Getting started was the problem, says the longtime Cooperstown-area resident.

"I was working for a construction company, and I happened to drive by when they had dug the hole for the theater," she remembers. "I was intrigued and wanted to find out what they were doing in Springfield Center. I discovered they were building an opera house, and I thought to myself, 'Hmmmm, that's curious. I like classical music.'"

A short while later she saw a newspaper ad for an assistant to artistic director Paul Kellogg and decided to apply. She didn't get the job. A few months later she saw an ad for a development assistant and applied for that job, too. Even a second strike-out didn't keep her from making a bid for a marketing assistant's job, when that one was posted a few months later still.

"I thought to myself, fLet me try one more time; three times is a charm,' and I came and I interviewed and I didn't get the job." Another three months rolled by, then Kellogg called her. The assistant he had initially hired didn't work out, and he asked Dropp whether she was still interested in working for the company.

"I was like, well, "Yes," and so I began and that was more than 17 years ago. The company was so small then I got to work in all the departments. I learned marketing from the ground up and also development, which is our fund-raising. I learned box office and ticketing and running the front of the house which is gift shop, concessions, security, parkers, maintenance. I got to do everything because it was 'all hands on deck' all the time."

a Dropp likes to joke that she's the director of everything that nobody else wants to do, and that's only a slight exaggeration at most. Her professional purview includes all the administrative aspects of the company and maintenance of all its facilities. She also makes sure that every artist and intern coming to Glimmerglass for the summer has adequate housing and transportation.

Glimmerglass will add a fourth opera to its rotating repertory on July 23, Britten's "Death in Venice," a co-production with the New York City Opera, where Paul Kellogg has been general and artistic director since 1996.

Co-productions, which Glimmerglass undertakes nearly every season, are another way the company extends its reach in the opera world. "Lucie de Lammermoor" is a co-production with the Boston Lyric Opera, where "Lucie" will bow in early November. Tomorrow night will be the first time in nearly a century that the French version of "Lucia di Lammermoor" has been heard in this country.

Glimmerglass has even begun a program to rent its scenery to other companies and recently bought a warehouse in Warren to facilitate things. "Glimmerglass Opera productions go all over the place now," says Jeryl Dropp. "They're going to be in Vancouver; they've been in Florida, at Florida Grand Opera; they've been to Opera Omaha and more places than I can remember. And they go with Glimmerglass's name on them."

Peter Wynne has written for Opera News magazine and the playbills handed out at the Metropolitan and New York City Opera, Carnegie and Avery Fisher Hall and the Kennedy Center in Washington.