At 9:30 on the morning of June 1, two firemen slept face down on cots off to one side of St. Paul’s Chapel. On the other side of the pews, Sharon Gunderson, clad in a flowing blouse, played Bach on her violin. A man wearing an NYPD badge stood nearby, listening. Today, the 700 concerts performed at the chapel over the last eight months were ending with an all-day music marathon.

Since the end of September, hundreds of professional musicians had played here for free, to audiences made up of emergency workers, coast guard personnel, firefighters, cops, sanitation crews, other volunteers and, most recently, construction workers, who spent time here between shifts at Ground Zero. Despite the hordes of volunteers and site workers, St. Paul’s Chapel maintained a peaceful, relaxed atmosphere, described by Officer Douglas of the NYPD as an “oasis of heaven in the midst of hell.”

But as the war zone of Ground Zero becomes a construction site, the chapel’s role is also being transformed. It closed on June 2 for its first major cleaning since Sept. 11 and will reopen to the public in several weeks, for the first time since the attacks (except for services on Christmas and a few other days).

On the porch, shielded from the Broadway throng by a collage of 9/11 banners that covers the church railing, I spoke to 802 member Ralph Farris, 31, who had organized musicians to cover the three daily meal-time concert slots, even when it meant calling friends at 2 a.m. the night before. “There will be a massive void in my life after today,” he said.

Farris has been busy as a professional violinist and violist throughout this period, playing in the orchestra of The Lion King and in his string quartet, Ethel. He spoke about how he had sometimes felt himself getting detached from his day-to-day routine of gigs before the attacks occurred. “Then I saw how essential music was to people grieving,” he said, “and this woke me up. Doing this has given me an opportunity to learn again what a blessing it is to be a musician – when I’m here I give it my all, and I’m noticing how much more I can give in other places.”

Look at an overhead photo that includes the WTC site and St. Paul’s Chapel, and you will be astonished that the 236-year-old brick and timber building survived the blasts. The church, which in 1789 was saved by a bucket brigade from a devastating fire that destroyed much of the city, sits one block west of what is now a 16-acre pit.

On Sept. 12 the Rev. Lyndon Harris, who is responsible for ministries at St. Paul’s, returned to the chapel to find the churchyard strewn with metal debris from the towers and covered in six inches of paper and ash. Inside, electricity and water were cut off and phone lines were dead – but miraculously, the building stood intact without so much as one broken window pane.

Since then, the chapel has served thousands of Ground Zero workers as a 24-hour doctor’s office, hostel, ministry, cafeteria, concert hall and temporary home. “It pained me to see the podiatrists in the George Washington pew,” said David Jette, the verger of mother church Trinity. “And yet, never have I experienced Trinity feeling so right…[or] more relevant to this neighborhood.”

At the height of rescue and recovery operations, St. Paul’s Chapel served 3,000 meals a day and slept around 80 workers each night on its cots and pews. This era came to an end the first weekend in June, when the last concerts were played and the last two Eucharist services were held. The first was for site workers and the second was for the volunteers who had served food, provided stationery for rescue workers writing back to school children, offered massage and chiropractic care, distributed eye drops and fresh underwear, provided counseling, and played concerts.

For Elinore O’Connell, a Broadway veteran who includes Ragtime among her credits, singing “Amazing Grace” at Sunday’s service confirmed her belief that the musicians had been part of the healing process. “It felt like an uplifting shift – we got through this dark period,” she said. “What got so many of us – the civic workers, and all of us – through, was grace.”

It had not been easy for musicians to get involved in Ground Zero volunteer work. Farris and his friens Wolfgang Tsoutsouris, a violinist, and Elissa Kleeman, a flutist, had wandered the city, offering their services as musicians. (Kleeman also organized a lip balm drive in New Jersey.) Several relief centers and two hospices for families of missing people turned them away. “It was horrible to know that we could make a difference and not be allowed to,” said Farris.

O’Connell, with the help of her businessman husband Niall Kelleher and singer colleague Linda Emond (who has just won an Obie for her leading role in Homebody Kabul), transformed their promotional website, www.usindiemusic.com, into a sign-up for The Music Givers, an organization that matched professional volunteer musicians with memorial services for victims of the attacks. When they heard about the music series at St. Paul’s, they began signing up musicians for performances here as well.

The concert series at St. Paul’s was shut down a few times, but gained stability when Local 802 caught wind of it. Hundreds of musicians had played in the series for free, but over Advent the union made funding from its Music Performance Trust Fund available to musicians who could use a paycheck. This helped several to pay rent that month, Farris said.

The informal atmosphere of St. Paul’s Chapel was a good home for volunteer musicians. “Ralph and the musicians transformed the place,” Rev. Lyndon Harris told me by e-mail. Their “soul-soothing” concerts were met with gratitude. Volunteer Lorraine Ashman, who worked as a kitchen captain from 8 a.m. to 8 p.m. every Saturday, agreed. “When you start losing it, you hear a strain of melody and it restores sanctity. And sanity!”

By 11 a.m. on June 1, two more musicians had arrived, and coals were started out back for the farewell barbecue. At noon, when the music stopped briefly for the Eucharist service, the narrow aisles were crowded with people and the pews were full. Rev. Harris wore a red chasuble stitched with round cloth badges representing hundreds of the teams of military, police, fire, sanitation and construction personnel who had visited Ground Zero from all over the world. Every last inch of the walls, backs of pews, columns and balconies was similarly covered with cards and letters from children to site workers. These disorderly displays of every hue contrasted sharply with the formal grandeur of the gold and white altar and the blue panes behind it. The decorations would all be coming down the next day, and stored for later study and display by the Smithsonian, the New-York Historical Society and the New York State Historical Association.

This impending housecleaning, and the changes that would accompany it, created a bittersweet atmosphere. “This is the end of phase one – but there is more grief work to be done,” said Rev. Harris during the service. In an e-mail a few days later, he wrote, “It’s hard to know at present what the future shape of ministry will be at St. Paul’s. It’s too soon.”

O’Connell had similar remarks about The Music Givers. “We originated this program to be a supportive team to the community, and however that is defined in the future will come from the community,” she said. “When needs appear, they will be addressed.”

Many people wept during the service, which ended with exchanges of hugs and tissues in the pews. But within minutes, four musicians were playing the “Hava Nagila” and, while many got in line for lunch, others spontaneously linked hands and danced around the pews in a human chain. When the song was over, there was applause throughout the chapel. “Was that cool or what?” asked one middle-aged woman volunteer. “I love the fact that we can do that in a church.”

Ralph Farris was beaming. His months performing here had been a gift not only to the workers, but also to himself. “I’ve recaptured what originally sparked me to become a musician.”