While the orchestra, in formal attire, tuned up for the first concert at the Music Center at Strathmore, guys in their best jeans craned their necks to point out to their girlfriends a particularly fine piece of woodwork, and guys with pagers clipped to their belts pulled their wives into a remote corner of the building to show off the complicated wiring, and Pierre Sicard beamed as he described to his entire family how he and his co-workers put up layer upon layer of drywall to create this showplace of acoustic science.

"I've never seen walls with so many layers," Sicard said, "three to five layers on some walls. It was amazing."

Hundreds of craftsmen and workers who toiled on Montgomery County's new arts center were treated last week to a Thank You Concert at the hall on Rockville Pike just north of the Capital Beltway. They couldn't stop raving about the workmanship of the job and the warm, intimate clarity of the sound. They wore their pride on their faces and in their embraces of each other.

And then, when members of the Baltimore Symphony Orchestra settled in, the hands-on creators hushed and assumed a new role as subjects in a grand physics experiment, the acoustical tuning of Montgomery's $98 million investment.

This was showtime for Carl Giegold and his fellow practitioners in the art and science of tempering a structure so it captures and delivers the sounds and emotions generated by a hundred world-class musicians. Giegold, who has worked on the Strathmore hall since 1999, has studied every wood, plaster and fabric in the place. He has used scale models, computers and machines that look like props from a 1956 sci-fi flick to develop strategies to keep out noise from voices in the lobby, traffic on the Pike and trains on the adjacent Metro line. The hall has been built with a huge empty vault beneath the floor so air conditioning and heat flows silently into the auditorium.

For weeks, musicians have rehearsed in the hall so Giegold and company could find the right positions for the acoustic panels and plexiglass clouds that float above the stage and over the metal-mesh ceiling. But no one knows what the hall will really sound like until the music washes over an audience of people and their coats and coughs and, ugh, candy wrappers.

"Musicians need to hear themselves and how they blend with their own sections and the whole orchestra," Giegold said. "The basses take cues from first violins 40 feet away, so the environment on stage has to support that with reflected sound."

How would it sound? The first notes of Maurice Ravel's "Rapsodie Espagnole" floated over the audience like a spring drizzle, and within minutes, the orchestra was pumping hard and a fully stocked percussion section was conjuring a Mediterranean festival, and onstage, the BSO's concertmaster, Jonathan Carney, couldn't contain a smile of satisfaction.

"It's gorgeous," he said later. "You can't tell anything till you get people in there, but it's clear and loud, incredibly different from Baltimore, where the sound is big and rich and not so clear."

Once public concerts begin, in February, the orchestra will be the first in the nation to have two year-round homes, as the BSO makes a play for a suburban audience that has had to head into Washington to hear the National Symphony. The musicians see this as a friendly rivalry; the people who sell tickets see more edge to the competition.

This is a pivotal moment in suburbia's generations-long struggle for an identity of its own. County Executive Doug Duncan risked the wrath of the anti-tax crowd to support Strathmore even through the inevitable cost overruns. The result is an exquisite space that will add to the life and learning of Montgomery residents, without the slightest expectation of a financial return on the investment.

(Note to opponents of the D.C. baseball stadium: Montgomery understands that one of government's jobs is to build infrastructure that improves quality of life, whether or not there's a profit in the deal.)

Outside, John Pylypec, an estimator for Overhead Doors, which supplied doors for the dock and interior, ran his hands over the corner where the hall's dramatic glass north wall meets a wall of stone. "The level of finishes is extraordinary," he said. "And the acoustics -- almost perfect. This is going to draw people big-time. Montgomery County really needs this. You watch: Build it and they will come."