It's as traditional as blisters and a sunburned nose - the familiar parting sight of an empty field under a carpet of litter.
One of those charged with cleaning up the mess calls it the "Big Day Out landfill".
But this year, organisers have decided to do something about it.
For the first time, festival-goers at Mt Smart Stadium will be asked to put their rubbish into separate bins for plastic, cans, food and other waste, watched by a team of recycling volunteers.
Jo Newman of the Ecomatters Environment Trust - who will help to co-ordinate the volunteers - said she did not know how punters would react to being asked to recycle, after past Big Day Outs left the site looking like a landfill.
Organisers hope music fans - expected to number at least 40,000 today - will help them to double last year's rate of 20 per cent recycling.
Last year, recyclable material was sorted from rubbish left littering the stadium after the event.
The new recycling push is part of a move towards more environmentally friendly behaviour by the music festival, Australasia's biggest, and by many of the artists who perform there.
People buying tickets for today's Auckland show had the option of paying $1.55 for a "carbon neutral day", calculated by dividing Australia's average greenhouse emissions for a day by the Australian population.
In 2007 and 2008, festival organisers planted 15,000 eucalyptus trees on an Australian farm to offset carbon emissions from the six annual shows, including Auckland. Sydney Big Day Out has run a successful recycling scheme for several years.
* Are you heading to the Big Day Out at Auckland's Mt Smart Stadium today? If so, we want to hear from you.
We'd like you to send us your photos from this year's event so we can feature them online.
Please include your name with your photos and - if it's not clear - what the photo is of.
Click here to send us your Big Day Out 2009 photos.