An all-women Christchurch barbershop chorus that has never been defeated nationally in its 40-year history is setting its sights on becoming the best in the world.

The Christchurch City Chorus has won every New Zealand competition it has entered and the a capella group finished fifth in the world two years ago.

But the singers are aiming even higher.

Every Wednesday evening they meet at the school hall at Redcliffs School to hone their harmonies.

Christchurch City Chorus co-director Heather Bentall described the group as "Christchurch's best kept secret".

"While we compete internationally and do very well internationally, really we are just normal people. We are just normal singers who sung in choirs at high school and decided to get back into singing as adults," she said.

"I think that can put some people off coming along and they think, I'm not good enough to be in that chorus. But really we're just average singers, you put them together and put some masterminds out the front and we create magical music together."

Bentall said the chorus' success could be traced back to the founder of the group Virginia Humphrey-Taylor, who discovered barbershop singing while overseas before returning home to establish a chorus in Christchurch.

What began with about 30 women in 1985 had grown into an award-winning ensemble of members ranging in age from teenagers to singers in their 80s.

"There's a bit of a saying we say that people come for the music but they stay for the friendship. I remember when I first joined the chorus, the thing that struck me most was how welcoming everybody was," Bentall said.

"Not only that, it's this massive well-oiled machine where everybody has a role to play, and it's just like one big family. You put 100 women together, it becomes a very well-organised organisation, and it's just a really joyful thing to be a part of."

The chorus is part of a bigger organisation called SingUnited International, previously known as Sweet Adelines, comprising about 400 all-women choruses across five continents.

The Christchurch group earned its highest international placing in Kansas City in 2024, climbing to fifth in the world after a performing a programme that included songs from The Greatest Showman.

After founder Humphrey-Taylor retired earlier this year, American director Ryan Heller has taken the reins of the group and is relocating from the United States after first working with the chorus as a coach more than a decade ago.

He said leading Christchurch City Chorus was an opportunity he could not ignore.

"When they made me aware of Virginia Humphrey-Taylor's retirement I said, if you're interested in a long distance applicant, keep me in mind and just half joking. But sure enough, they did their search at the end of last year and said, you know, if you're serious, go ahead and submit your materials. And here I am," he said.

"These singers bring a skill set that's just second to none."

The group's immediate goal is to defend its unbeaten national title in 2027 before qualifying for the international championships in Seattle the following year.

"We are dreaming into the future right now. We are coming up with new repertoire, long range plans for what we want performances to look like. I want us to be the first New Zealand chorus champion. If that happens in 2028, great. But if that takes some years, that's fine too," Heller said.

"We're in it for the long haul, always trying to better ourselves, always to figure out what is it that most excites the audience, because that's really, at the end of the day, what is being rewarded. When the crowd leaps up to their feet because it was such a thrilling performance."

The performances combine intricate four-part harmony with choreography, but Heller said the appeal of barbershop went beyond technical precision.

"The sound itself is a physical experience. When all those voices are locked in, when everything is synchronised, when everything is immaculately in tune... people typically have a physical reaction. They might get goosebumps, they might get chills, they might be moved to tears or laughter, or whatever it is that the emotional energy is carrying," he said.

The chorus is a charity funded through membership fees, fundraising and grants.

The love of the music had kept 82-year-old Miriam Spragg coming back for nearly three decades.

This longtime chorus member received a King's Birthday Honour this year for services to barbershop singing and music administration.

She said singing in the chorus was addictive.

"There's always that little carrot that makes me want to stay in for another contest," she said.

"Once through that door, you're just hooked. It's like a great big fishing line just grabs you, it's just such an amazing feeling with the music."

Ballads were Spragg's favourite songs to perform.

"That's when you stir people's emotion up and touch their hearts, and you have beautiful overtones that just make them shudder and think, how do we do this?" she said.

Liz Slade, who had been a part of the group for more than 20 years, said the chorus was her second family.

"I'm so proud of us as a group, as individuals and what we can achieve together," she said.

"We do it because we love it and we keep coming back because the people are just so special and there's no way of explaining exactly how it makes you feel until you walk in the room. When you walk in the room you get it."