Though it's too soon for full assessments, musicians of the St. Paul Chamber Orchestra gave high marks to their new $42 million hall on Wednesday.

"It feels spacious — we're not boxed in," said concertmaster Steven Copes, just before the orchestra's first rehearsal in the soon-to-open Ordway Center Concert Hall. "Even warming up, you can tell right away the space is responsive to the sound. And it's beautiful, all those undulating lines."

Kyu-Young Kim, principal second violin and senior director of artistic planning, called the sound "vibrant, warm, with a beautiful sheen and the clarity of individual voices. Now it's just a matter of enhancing, playing here enough to figure out how to optimize the space, and we have the luxury of six weeks to do that."

The nearly finished 1,100-seat space doesn't open until Feb. 28. Designed specifically for a chamber orchestra and its audiences, the hall will also present a variety of pop, world-music and choral concerts and, since it also features a sprung floor, dance performances.

The hall, which replaces the McKnight Theatre, has a banded-glass exterior in keeping with the original building designed in 1985 by Ben Thompson. Two serpentine balconies wrap around the walls with another small seating area behind the stage. No seat is more than 90 feet from the stage.

Its most striking features — a ceiling covered in graceful, wavy panels of mahogany-stained dowels and alabaster-colored side walls with bas-relief, abstract cylindrical shapes — seem an apt visual representation of the sound emanating from below.

But it is not intended as a direct musical metaphor, said the hall's architect, Tim Carl of the Minneapolis firm HGA.

"The musicians didn't want anything that literal, but they did want an intimacy, with the audience feeling embraced by their surroundings," he said.

Carl, who worked closely with acoustical designer Paul Scarbrough, said that almost every aspect of the plan has acoustical purpose. The irregularly spaced ceiling dowels allow for sound transparency. The fluting on the walls, clustered in varying numbers and sizes, creates diffusion of sound.

The hall was built by the Arts Partnership, a group made up of the Ordway and its three principal users, the SPCO, the Minnesota Opera and the Schubert Club. Its completion will reduce programming pressure on the facility.

The partnership's capital campaign has raised its goal of $83 million (up from an original $75 million forecast in 2007) for the 56,000-square-foot expansion and an endowment fund, making it the most ambitious arts institution remodel since the $125 million Guthrie Theater relocation.

Bruce Coppock, SPCO president, called the day "an emotional one for me. We've been working on making this happen for 15 years."

The orchestra, which performs about half its concerts at other metro venues, previously played at the larger, adjacent Music Theater, which seats 1,900. That space is well suited to opera and musical-theater productions (which will continue there) but has been criticized for fuzzy orchestral acoustics.

"Halls that start out acoustically problematic tend to stay that way," said Kim. "This [new hall] is not going to be one of those halls."

Several construction workers still working on the lobby were among the rehearsal audience, hard hats in their laps. Asked if he'd be likely to attend more orchestra concerts after hearing the performance, one of them shook his head.

"It's not really my thing," he said. "It sure sounds great, though."

Kristin Tillotson • 612-673-7046