This year's finale of Minnesota Orchestra's Sommerfest, a semi-staged performance of Puccini's "Tosca," is a real family affair. Soprano Barbara Shirvis sings the diva Tosca. Her husband, baritone Stephen Powell, sings the villain Scarpia. And their 11-year-old son, Benjamin Powell, sings the offstage Shepherd Boy.

Shirvis and Powell, who live outside Philadelphia, work together frequently, but this is the first time that all three family members have appeared in a production. Shirvis initiated the arrangement.

"I told them, 'I am the best soprano in my price range and I come with my own Shepherd Boy.' Just call me Mama Rose," she said, of the quintessential stage mother in "Gypsy." " 'Sing out, Louise!' "

Only 11, Benjamin has a fair amount of stage experience. He and his brother Zachary, who's 9, recently played pages in a production of Verdi's "Falstaff" in Tulsa, Okla., where Shirvis sang Alice Ford. "In one sentence, the stage is fun for me," Benjamin said. "Opera is fun to watch and listen to."

"He can't escape it," his father said ruefully.

Benjamin already has a clear sense of his potential future. "If I go into opera, and I may, I think I'll sing Falstaff. I want to go for title characters."

They met at the Met

Shirvis and Powell's personal and professional relationships have been intertwined from the beginning. They met while singing together at New York City Opera, sharing the stage in "Magic Flute," "Cosi fan Tutte" and "Mikado."

Having met doing shows, Powell said, "we became comfortable together on stage and that became the foundation of our relationship."

Still, they admit that it's hard to facilitate two careers and a family, especially when so much traveling is involved. They made the decision to home-school their boys, so they would be free to accompany them.

But they deny any form of professional competition. "We believe in each other," Powell said. "And we're supportive of each other, especially if one of us isn't getting the recognition they deserve."

"We're a family," Shirvis said. "His success is the success of the family. Just as my success is the success of the family."

The fact that Shirvis has sung Tosca before and this is Powell's first outing as Scarpia might present the temptation for her to offer advice, but, "Heavens no! I stay out of that," Shirvis said.

But she's happy they're working together. "I can relax onstage with him. There's a lot of physicality in 'Tosca.' " (Scarpia attempts to rape Tosca, for one thing.) "I can trust him not to be a wild card."

They also have worked with director Robert Neu in other semi-staged productions. "I hate it!" Shirvis said of the format. "I understand the need for it. Opera is so fricking expensive."

"But it's way more difficult," Powell added. "We call it 'semi-rehearsed,' trying to do a full production in five days. And being in front of the orchestra, it's more difficult for the musicians to stay together."

That said, Shirvis sees advantages for the audience. "Especially with Puccini, there are so many colors in the orchestra. They can focus on that."

And both are thrilled to be working with Neu again.

"He's very good at what is a very difficult way to do opera," Shirvis said.

William Randall Beard writes frequently about music.