Roxburgh percussionists Daniel Dance and his nephew Jesse Orchard, and Alexandra cornet player Sarah Wright will join the Ascot Park Hotel Brass Band from Invercargill, which was selected to perform in the festival.
A concert in Alexandra next week will help raise funds for the trip.
Mr Dance said he had played with the Invercargill band since 2001, but the two youngsters were head-hunted for the festival.
''Jesse played for us in the nationals last year. Unfortunately, one of our members can't come and a mate asked if Jesse would want to play.''
Sarah was heard by the band leader while playing for the New Zealand Secondary Schools Brass Band, he said.
The younger two have never played while marching, but will have to do so over 3km in the festival.
''They'll get a bit of a crash course this weekend on how to do it.
''It'll be 35-degree heat, too, so that might be a bit of a wake-up call,'' Mr Dance said.
All three play in the Roxburgh Pioneer Brass Band.
Band chairman Doug Dance, who is Daniel's father and Jesse's grandfather, said as well as helping with expenses, the fundraising concert would showcase the talents of the musicians.
''It shows you can play at a high level in a small country town like Roxburgh.
''We've always been quite competitive.''
The Roxburgh band will play at 7pm on Wednesday, at the Dunstan High School Hall. It will be joined by guest artists from the school and Verdon College, in Invercargill.
