"Under level 1 New Zealand was the only country where choirs could rehearse and perform together," Overtones co-director Liz Watts said.
This was their first performance since lockdown.
"It was great to get out and sing for OnStage."
Their performance was compensation for missing the cancelled national championships in Wellington in May.
Watts missed a bigger trip to Belgium for the Sweet Adelines' 75th anniversary celebration.
A group formed from around New Zealand, singing as He Tangata, was to take part, but Covid intervened there also.
As long as level 2 lasts, the Overtones will continue rehearsing even if they can't perform.
It can take as long as six months to perfect the harmonies and choreography for numbers in their OnStage programme, such as Michael Buble's Everything, Adele's Rolling in the Deep, and the gospel number When I Lift up my Head.
"Our members are pretty determined.
"About a quarter of them are from outside the city – as far away as Whanganui," Watts commented.
"It's quite a tradition nationally.
"The Overtones are about 14 years old but the Sweet Adelines have been in New Zealand for 35 years."
The women come from many walks of life; scientists and lecturers, to the director of helicopter operations at ōhakea, teachers, nurses and the Horizons council's education section.
"Of course, we're always looking for more singers – especially basses," she added.
Watts is a baritone.