The Thames Music Group is hosting the Mighty River Harmony in Thames on August 13.
The group is an auditioned, a cappella chorus of about 20 men, mostly from the Waikato.
They sing four-part harmony, often in the barbershop style.
For the past 30 years the chorus has been one of the top barbershop harmony groups in New Zealand.
Most of its singers are seniors but they also sponsor the mixed youth chorus Manu Mātātahi.