"I've always loved singing -- but Parkinson's has affected my voice the most," Ms Chadwick said.
"But I wanted to keep singing for as long as I could.
"People with Parkinson's don't want to stop doing the things they liked before they got unwell."
Ms Chadwick said the choir is an extension of the LSVT Loud speech therapy programme for people with Parkinson's, recently adopted by Wairarapa DHB.
The programme helps Parkinson's people improve vocal loudness, intonation and intelligibility by stimulating the voice box.
DHB speech therapist Sarah Martin, who leads the Sparkin' Songsters in vocal warm-ups, said Parkinson's can have a dramatic affect on speech clarity.
"With Parkinson's, movements and sounds tend to get smaller.
"People's voices tend to get softer and quieter, and that can cause real difficulty."
Singing, however, gets people using their voice, and helps to improve vocal projection, breath control and articulation, she said.
"It's a great way of communicating".
Ms Chadwick said Parkinson's Wairarapa members were initially hesitant to join a choir and so she was pleasantly surprised when more than 30 people turned up for the first session.
"Lots of people said they couldn't sing.
"But they're enjoying it so far -- one lady told me this is the first time she's sung in 30 years, and she loves it.
"And Vicki is really empathetic and makes it fun."
Members are also enjoying the social aspect, particularly for those who haven't been able to participate in other groups, such as exercise classes, because of limited movement.
Eventually, the group hopes to perform at rest homes and events such as The Twelve Nights of Christmas.
The Sparkin' Songsters have received a grant from South Wairarapa District Council's Creative Communities scheme to cover the costs of tutoring, stationery needs and catering, and the Workingmen's Club have given the group free room hire.
For more information about the Sparkin' Songsters, call Marguerite Chadwick on 06 379 3576. Membership is restricted to people with Parkinson's and their caregivers. The group is also in need of a pianist.