SALEM — A cacophony of sound drifts out of Salem's Old Town Hall and over the steamy summer air.
Shortly before 8 p.m., instrumentalists in the second-floor meeting hall are tuning up, while vocalists and visitors chat together before the Paul Madore Chorale SummerSing, an all-comers' evening of classical music that doubles as a fundraiser for the Salem-based group.
But when guest conductor David Callahan lifts his baton, order begins to take shape, and the musicians embrace Mozart's "Requiem" as one cohesive orchestra.
For three decades, SummerSing has drawn music lovers who want to play classical pieces as part of an orchestral ensemble or sing as part of a chorus. Adults pay $8 and seniors and students $6. Some people just come to listen.
Despite the formality of the music, the weekly singalong takes a surprisingly casual approach.
"We never know how many singers we're going to have, and that's the fun of it," said Mary Pelletier, co-founder of SummerSing.
Most of the 100 or so participants wear summer attire, shorts and T-shirts. Fans placed around the room do their best to cool a 180-year-old upstairs space without air conditioning. The heat doesn't dampen the fun or the energy.
The group spends the first 45 minutes or so rehearsing certain sections, then takes a brief break before diving into a work from start to finish.
"We start and everything becomes quiet and businesslike," Pelletier said. "We go through the whole thing uninterrupted, and it goes and it's magical."
Pelletier and Trudy Hill, the other SummerSing co-founder, met as members of Madore's chorale. Years ago, they atten-ded a similar singalong in Boston and decided to create their own for Salem and the North Shore. Hill and Pelletier decided to broaden the idea by inviting instrumentalists.
The result has been inspirational and surprising, Pelletier said.
"This is the most wonderful part of SummerSing," she said. "It doesn't necessarily mean we do this because we want to raise money. The goodwill that is generated by this happening in the middle of downtown Salem at Old Town Hall is quite miraculous."
For nine weeks this summer, SummerSing hosts a guest conductor to lead the volunteer musicians through a master work. Next week, Dirk Hillyer will conduct Handel's "Messiah."
Pelletier, an 83-year-old mother of nine, does most of the public relations and hands-on work for the evenings. By the end of the series, she hopes to take in between $1,000 and $2,000 for the chorale.
Hill, along with Madore, selects the conductors and the soloists. A classically trained singer, Hill also prepares the programs for each session.
For the pair of die-hards, SummerSing is a labor of love. But it has plenty of rewards.
Passers-by hear the music and are drawn up the two flights of stairs to get a glimpse at the musicians.
Earlier this month, a woman heard the music and came up the stairs, Hill said. Tears were streaming down her face.
"This is how music affects people," Pelletier said.
"I hugged her several times," Hill said, "and she thanked me after."
Neither of the organizers knew the woman's story, but they understood.
SummerSing is held every Monday during the summer at 8 p.m. at Old Town Hall, Derby Square, Salem. Admission is $8 for adults, $6 for students and seniors.
July 26: Selections from Handel's "Messiah," conducted by Dirk Hillyer
Aug. 2: John Rutter's Requiem, conducted by John Koza
Aug. 9: Carl Orff's "Carmina Burana," conducted by Max Hobart
Aug. 16: Antonio Vivaldi's "Gloria" and Gabriel Faure's Requiem, conducted by William Sano
Aug. 23: Felix Mendelssohn's "Elijah" (with cuts), conducted by Paul Madore
Aug. 30: Giuseppe Verdi's "Manzoni Requiem," conducted by Jeffrey Brody