Earlier this year, the barbershop chorus won the small chorus section at the annual National Barbershop Convention in Wellington.
Bishara discovered the Overtones from an internet search and had wanted to be a part of a choir for a while, but never found the time.
"Coincidentally, they were having an open night the following week, so I attended that and absolutely fell in love with it," Bishara said.
"It was the fellowship of it and I found out they were a group that provides a lot of entertainment for community organisations."
The Overtones perform in what they call "sing outs" which can include rest home visits, birthdays and Christmas carols at malls.
Originally from the Waikato, Bishara moved to Marton in 1986 and has a musical background.
"Having a religious, Māori background, we did a lot of singing in church, all of my whanau sung and it came naturally," Bishara said.
"It was part of our culture."
Joining the Manawatū Overtones at the concert will be the Nga Tawa School and Huntley School choirs.
"Our director Sylvia attended The Big Sing. She saw Nga Tawa there, was impressed and suggested we have some local content.
"Both Nga Tawa and Huntley schools have a barbershop element to their choirs. It means they're extending their experience by watching us and learning from us and vice versa."
The Manawatū Overtones meet every Tuesday night at the Scottish Society Hall in Palmerston North from 7pm until 9.30.
Concert tickets are $5 for adults, $2 for school children and under 5s are free.
They can be bought at Sassy's Hair Boutique in Marton and Intrigue Boutique in Bulls.
