The Wolf Trap Opera Company at Wolf Trap Farm Park in Vienna has become a prime training ground for American opera talent.

A look at the list of alumni from the company reveals a who's who of the American opera community. In fact, the current issue of Opera News, a leading publication for opera lovers, lists six current or recent members of the company among the 16 young American singers that it says are on the rise.

The Wolf Trap Opera Company began in 1971 with the charge of bringing the best young American opera singers together to prepare them for professional engagements. Members of the nonprofit professional company are chosen from more than 700 applicants by music director Richard Woitach, artistic consultant Francis Rizzo and administrative director Peter Russell.

For its 17th season, the company has hired 15 singers ranging from 23 to 29 years old and a 13-member technical staff of students ranging from 18 to 28 years old. Participants are limited to two years with the company.

For young singers, Wolf Trap provides the opportunity to perform roles they would not get if they were with a major company, while the backstage technicians, who come directly from university theaters, learn to deal with the pressures of the professional stage.

"A lot of kids coming from schools that have built theater departments in the last 10 years are used to working in a space that is impeccably designed," production manager Bob Grimes said. "We fall somewhere in between that and the storefront theaters that a lot of people are working in."

Directed by a handful of paid staffers, the technical interns produce two full sets from scratch to be used in the Barns, and a simple set for the children's Theater-in-the-Woods.

When the company moves over to the Filene Center in August for its performances of Benjamin Britten's "Midsummer Night's Dream," the sets will be brought in from an acclaimed production designed by Ottawa's National Arts Centre. While the Filene Center performances focus attention on the singer's ability to project a more powerful stage persona, the more intimate Barns offers a space where the singers can demonstrate subtler points of diction and staging.

It is under these more controlled conditions that the singers can make their mark on the directors and agents who shape opera careers.

For example, last Friday's performance at the Barns coincided with a Washington meeting of Opera America, the trade association of professional American opera companies, and as many as 50 representatives from member companies were in attendance.

The opera company's artistic consultant, Francis Rizzo, says that watching a singer in performance is a better way to judge his talent than in an audition. Many of the company members do not yet have work scheduled beyond the summer, but they say that playing challenging roles inevitably opens doors.

Stanford Olsen, a member of the company who portrayed Count Almaviva in "The Barber of Seville," is among those named as a promising artist by Opera News. He comes to Wolf Trap after making his Metropolitan Opera debut opposite Dame Joan Sutherland in "I Puritani," filling in for the ailing Rockwell Blake, who was a participant at Wolf Trap more than a decade ago.

Olsen said Wolf Trap offers the opportunity to build a solid role that he can repeat in other performances with other companies. "I wanted to do this role," Olsen said. "It's a role that I think I can sing well, and because the opera gets produced so often . . . I should be able to get some work out of it."

Olsen has not been left entirely to his own devices in developing his Almaviva. Along with the rest of the cast, he has built his character under the watchful eye of stage director Andrew Foldi, who has sung in more than 300 performances of "Barber."

"The interesting thing about them," Foldi said of the Wolf Trap group, "is that they're all doing the roles for the first time." That brings a special responsibility to the director, he said, "because the first time someone undertakes a role, the preparation for that lasts an entire career."

With so many successful singers coming out of the Wolf Trap program, it is easy to wonder which ones among the current crop will go on to international success. But Foldi, the veteran director, warns that it is not easy to predict.

"Occasionally you run into someone where you think, 'This person can't miss,' and half the time you're wrong," he said. "And also occasionally you run into people, much earlier in the game, when you say, 'This person shouldn't be in the profession,' and there, I'm sorry to say, you're right 100 percent of the time.

"But most of the time you have a huge gray area, which is probably 98 percent of the people that you work with, where it depends on so many different factors."

Those many different factors will come into play once again tomorrow night with the opening of the company's second production, Francesco Cavalli's "L'Ormindo."