Up to 45,00 music fans are expected at a music festival on Friday at Mount Smart stadium in Auckland.
The Big Day Out will have more than 70 acts. Neil Young is headlining the event.
Organiser Campbell Smith says it's only once in every five or 10 years that New Zealand is able to see an act with Young's stature and significance.
Rock, dance, hip-hop, electronica and indie acts are also on offer throughout the day. Among the line up are pop duo, the Ting Tings, and electronic act, the Prodigy.
St John Ambulance says people going to the festival should wear sun-screen, comfortable shoes and stay well hydrated.
The event begins at 11am.