GUELPH — Inside a rural public library on a chilly December night, a dozen snowy-haired men are rousing a crowd with an a capella rendition of The Beach Boys’ “Kokomo.” Swaying to the strains of “Aruba, Bahamas …” they have the energy, and the jazz hands, of a teenage glee club.

The Baker’s Dozen is part of a larger barbershop chorus called the Royal City Ambassadors, which has been performing in Guelph and surrounding communities for the past 45 years.

They’ve been a part of the community for almost half a century, but their numbers have recently been thinning.

Ralph Tersigni, who’s been a member for 14 years, says many of their singers are simply getting older. They’ve also lost a few members who’ve passed away.

“In a couple of years if we can’t grow, at the age we got now, we’re out of business,” he says, taking a break from performing as an enchanted audience sips on cider and nibbles on Christmas cookies.

“In 1999, we had close to 70 members,” he adds.

Now they have around 35, 25 of which come out to harmonize at regular Tuesday night practices at Ignatius Jesuit Centre. They sing at churches, theatres, retirement homes, community centres and public parks. They used to do an annual show but they no longer have enough singers.

Tersigni hopes that a planned recruitment drive in February will attract some new blood and allow them start the annual show up again.

He will teach new members to read music for free to sweeten the deal.

“The more in the group, the better the sound,” he says.

The world has changed a lot since it first started, back when computers and smartphones didn’t exist and most TV was in black and white.

The Royal City Ambassadors first started singing in the 1950s, but became affiliated with other barbershop choruses across North America about 45 years ago, says Tersigni.

They’ve been crooning classics such as “Sentimental Journey” and “Under the Boardwalk,” at fall fairs and plowing matches ever since.

They occasionally compete, but mostly “sing for the love of singing,” he says.

They also donate proceeds — after rent and royalties — to two charities: Harmonize for Speech, which helps kids with speech problems, and Sing Harmony Canada, which provides support for kids to continue musical education.

One of the spryest members, despite being well into his 80s, is tenor Kenny Graham.

Donning a Rudolph-style red nose for a spirited version of “Deck the Halls,” Graham shimmies with a giant grin on his face.

“I can’t keep still,” he says.

He has been a member for 38 years.

“It’s a great hobby and it’s been a lot of fun,” he says.

“And we help kids with hearing problems, so that makes it even better.”

Bass Jim Hopkinson says they’re “in the building process,” trying to get their numbers up to where they once were.

He has been hooked on the group for decades, ever since a co-worker told him about it in the 1960s.

“I went down and heard them one night, and went back the next night. And the third night I fell in love with it,” he says.

“Been here ever since.”