Tom Rossin had his "Field of Dreams" experience in 2019. But instead of building a baseball diamond on his farm, he felt called to construct a concert hall in his Eagan home.

"We'd been talking for years about what we want to do in retirement," Rossin said of himself and his wife, Laurie Rossin. "We want to help emerging artists. So we have concerts here."

What once was a deck on the back of their house near the Minnesota River Valley is now a towering concert hall with a sloping wood ceiling, a two-story wall of windows and seating for up to 50.

On Friday night, Rossin Music Hall will be hosting its biggest performance yet, the North American premiere of Welsh composer Paul Mealor's concert opera "Gelert." It will be performed by Exultate, the choir and chamber orchestra that Rossin has conducted since cofounding it in 1996. That concert is sold out, but "Gelert" will be repeated at St. Paul's Sundin Music Hall on Saturday evening.

It's quite a coup for Exultate, as Mealor has been among the United Kingdom's most popular composers ever since his "Ubi Caritas" was performed at the 2011 wedding of Prince William and Kate Middleton. More recently, bass-baritone Bryn Terfel premiered Mealor's Welsh-language "Kyrie" at King Charles' coronation. Now the composer is in the Twin Cities for "Gelert," as is librettist Grahame Davies, one of Wales' most renowned poets.

It's an unusually large-scale piece for the relatively intimate confines of Rossin Music Hall, but a fine coming-out party for Rossin's dream venue, an arched room with two chandeliers, including one reminiscent of a crystal ice cream cone that spirals downward toward the hall's grand piano. The walls are adorned with musically themed paintings, prints, CDs and cover art from Exultate's 30-plus albums.

The group's specialty is works that employ both a choir and orchestra by such composers as J.S. Bach, Mozart, John Rutter — and Paul Mealor. That composer's "Gelert" is based on a popular Welsh legend of a faithful wolfhound mistakenly killed by a prince.

Before his tenure with Exultate, Rossin was associate conductor of the National Lutheran Choir and director of choral activities at Augsburg University and St. Cloud State University. He's also a software developer who helped invent Apple's QuickTime multimedia architecture.

"The room is also a recording studio," Rossin said, gesturing to wall jacks behind the piano. "We plug in here and it goes right up to my office." He pointed to an upper-level window looking down upon the hall.

There in summer 2021 Exultate recorded J.S. Bach's complete motets, sung in both German and English by a group of fully vaccinated and oft-tested musicians. The hall's first concert was a recital by one of those emerging artists it was built to showcase, pianist Evan Shinners.

"If he's not the best player of Bach for keyboard in the world, I don't know who is," Rossin said. "Then we did eight or nine hours of recording sessions.

"Normally, for a recital, we can have 50 people in here. Everything's on wheels. It's really easy to set up, and everything is stored downstairs beneath us, because we dug out a basement underneath with an elevator leading to it."

The hall's ceiling is made of fir, the floor of hickory. Rossin is particularly proud of the room's acoustics, which he crafted with the help of acoustician David Braslau.

"There are only a couple of right angles in the room," Rossin said. "It makes the sound travel everywhere. It sounds the same no matter where you are in the room."

Recitals are in the works for baroque cellist Charles Asch, violinist Sarah Wright and possibly some other Exultate musicians. When they're announced, tickets will be available at exultate.org.

Exultate
What: Paul Mealor's concert opera "Gelert."
When and where: 6:30 p.m. Fri., Rossin Music Hall, 1433 Highview Av., Eagan; 7 p.m. Sat., Sundin Music Hall, 1531 Hewitt Av., St. Paul.
Tickets: $35-$10, available at exultate.org.

Rob Hubbard is a Twin Cities classical music writer. Reach him at wordhub@yahoo.com.