Singers feel the joy down in their molecules

Two days after the Boston Marathon bombing, a sellout crowd at the TD Garden stood and sang “The Star-Spangled Banner.”

It wasn’t the usual perfunctory mouthing of the words: This audience sang at the top of its lungs.

The electrifying moment did more than just kick off a Bruins game. It opened a channel, linking the spectators — and even with those watching on television — and instead of falling apart in a moment of tragedy, the song helped them hang together.

“It was a show of solidarity and strength and ‘We’re going to get through this and we’re going to get through this together,’ ” writer Stacy Horn said.

In the book “Imperfect Harmony: Finding Happiness Singing with Others,” Horn writes about the magic that happens in the web of joined voices, a power that makes the worst things bearable and the best things even better.

This season, at this most sociable end of the year, Americans seem to find their voices raised in song more than at any other time.

Church-goers join in hymns, neighbors go wassailing and community sing-alongs enliven the air.

Shower-singers who might never glance at a sheet of music the rest of the year try out ambitious works, including those who will sing a pickup version of Handel’s “Messiah” on Sunday at Roswell United Methodist Church.

Michael O’Neal, the director of the Michael O’Neal Singers, conducts the volunteer chorus, which should top 800 this year. Each singer brings his or her own score (or buys one at the event), and the only rehearsal is a quick 15-minute walk-through.

“We can take it seriously,” O’Neal said, “but we don’t have to take ourselves too seriously.”

What the performance lacks in precision it makes up for in power and emotion, he said.

“The whole thing about live music making is: It’s live. And it’s imperfect,” he said. “And that’s one of the joys of it.”

O’Neal’s choirs are all volunteer and pay for themselves by ticket sales and dues from members. The dues are worth it, the members say.

“There is such a joy that comes from singing in a choral group,” said Cookie Stokes-Preuss of Dunwoody, a member of O’Neal’s summertime group and a regular participant in the “Messiah” sing-along.

“It’s a wonderful challenge,” Stokes-Preuss said, “and I’m learning to accept the challenge without shaking in my boots.”

Americans are prickly about singing in front of each other. They insist they “can’t sing,” that they’re not good enough. The gladiatorial competition in such television shows as “American Idol” and “The Voice” exacerbates this tendency, Pine Lake musician Elise Witt said.

Yet Witt, who has conducted choral workshops across the country, knows there’s a demand, “a hunger for nonperforming, community-oriented singing.” For a while she has been organizing a regular event called “An Impromptu Glorious Chorus,” at which, for a small fee, participants find themselves singing in harmony, beyond their expectations.

The result is transformative. “It’s a physical vibration,” she said, “so it literally changes your molecules.”

Witt, like many of Atlanta’s choral directors, sang under Robert Shaw in the Atlanta Symphony Chorus, one of the world’s great choral groups. Shaw’s imprint can be seen in choral groups throughout Atlanta, and he is one reason the city is a great place to sing.

In Atlanta, and elsewhere, there are signs that group singing is making a comeback, including the popularity of “Glee,” the thriving a cappella scene and even such YouTube moments as the vignette showing an audience at Wembley Stadium in London bursting into a spontaneous rendition of “Bohemian Rhapsody.”

For Horn, this is a good thing.

“When I sing in harmony, it’s like coming alive,” she recently told The Atlanta Journal-Constitution. “Nothing else in my life gets me to that state. The closest thing is that rush from falling in love.”

O’Neal agrees that singing can make the world a better place. He knows how much his singers get from their regular practices.

“People come after working all day, and after fighting Atlanta traffic,” he said, “and they say ‘I didn’t know how I was going to get the energy to come to rehearsal, and after 2 1/2 hours I feel rejuvenated.’ ”