Members of the Choo Choo Chorus hope to post some impressive numbers in a concert Saturday, Dec. 8.

They're doing the math in multiples of 10: The goal for this 10th anniversary Community Christmas Chorus concert is to fill the stage with 100 men and raise $10,000 for the Walter E. Boehm Birth Defects Center.

"We've had great attendance at each of the practice sessions, averaging 75 to 80 people at each training, and each time there were different faces in the crowd," said publicity chairman Marcellus Scott. "We believe we'll surpass 100 once everybody is present."

That will make it "the largest male chorus to perform in Chattanooga in our memory," he said.

In addition to members of the Chattanooga chapter of the Barbershop Harmony Society, there are singers from the Sound of Tennessee Chorus in Cleveland and the community at large. Chapter leaders sounded a call for participation in late September, and the singers have been rehearsing weekly since. Their ages range from a returning charter member to a newcomer middle-school student accompanying his music teacher.

The Choo Choo Chorus is marking 50 years of service to the community this year, according to member Steve Wixson. Charitable giving has long been a priority for the organization.

"Last year we raised $5,200 for Boehm, and it looks like we can meet our 2012 goal of $10,000 with the large group of men singing and selling tickets," he said. "In addition to the show, all of the proceeds from our Christmas singouts (Alexian Grove, Military Officers Association of America, Garden Plaza, Fairview Baptist Church, Alexian Village and Rock City) go toward this goal."

This year's program will include a parody of "A Christmas Carol," called "What the Dickens," as well as classics that promise to be truly moving, Scott said. Among them: "O Come O Come Emmanuel," "Mary Had a Baby" and "It Came Upon a Midnight Clear."

"Those are three standout numbers that I think folks will really go nuts over," he said. "The arrangements and harmonies are wonderful."

One song, he teased, is being kept secret. It's a little out of the ordinary, Scott said, but "it ties right in to Christmas tradition, and I don't believe it's ever been done on a stage in Chattanooga before."

Contact staff writer Lisa Denton at ldenton@timesfreepress.com or 423-757-6281.