"It's a huge commitment," he said.
"Getting towards the big day there are full weekend practices, midweek practices and individual preparation.
"There are many hundreds of hours of work from a multitude of people, right from the composers and choreographers to the performers and all their supporters."
But also at work have been dozens of people transforming Kahungunu Park, now fitted with a stage the size of a major rock concert platform
This is flanked by the mahau, a 13-metre span stretching 13m high carved by members of the New Zealand Maori Arts and Crafts Institute, where it was used for Te Matatini for the first time in 2013 and described at the time by institute director Karl Johnstone as a "taonga for the nation".
Its timbers are all natives, and include a huge kauri carbon-dated 4500 years old, and it illustrates the regional styles of Maori wood carving.
Mr Barber said "The stage we practise on is relatively small. When you walk out at Te Matatini it feels like a football field."
But he said it was crucial not to get overwhelmed.
"We have 25 minutes from start to finish and we have to make the most of it," he said.
"We have to all give 100 per cent, and we will."