Phoenix Foundation dreamt up NZSO collaboration at the pub

Some of the most brilliant and outrageous ideas are often brewed in a pub - but unlike most of those ideas, this one actually came to fruition.

Wellington icons The Phoenix Foundation were thinking of a way to celebrate their 20th anniversary.

"There's sort of no better way to celebrate the music you've made than to actually perform it," says co-founder Samuel Flynn Scott.

And they're marking the occasion in a way few bands have ever had the privilege of - adding a string to their bow and hitting the road with the New Zealand Symphony Orchestra (NZSO).

"We're applying a lot of pressure on ourselves because the potential is so huge for it to be so awesome," says co-founder Luke Buda.

Buda was approached by NZSO conductor and friend Hamish McKeich a year ago - but the band was initially hesitant, as they didn't want it to seem like a gimmick.

"You don't want to do it just as a token gesture, you want to make sure it's done right," says Buda.

"You want to use the full capacity of the orchestra, and the full skillset of everyone involved," adds Scott.

It means rather than simply use the NZSO as a backing band, the Phoenix Foundation are keen to collaborate with them at every opportunity in the songs - even if it means taking a back seat.

"We're just keeping an open mind, and open ears, and of course an open heart," says Buda.

With rehearsals almost done and the first show in Wellington on Thursday, they're confident they'll be the best gigs they've ever played.

"The players in the NZSO are pretty good, so they just kind of get everything right from the first go, which is a very unusual experience for us," says Scott.

"We might start taking them on tour. We'll probably talk to our manager about budgets and stuff, see if we can get that in there. Doing gigs down at the San Fran, see if we can find a spot for them on stage," says Buda.

The band says they never dreamed of this sort of collaboration- in fact, they never dreamed they'd get this far.

"I don't think back then I'd have thought about myself at 40 at any point. I'd have thought, 'Yeah! I'm 18! And I've got an electric guitar!'" says Buda.

Fans can expect not just the classics but deep cuts across their whole catalogue re-arranged by composers for the occasion.

"There's I think not quite enough of your songs in the setlist," Scott says to Buda. "But I didn't pick the setlist, so I feel a weird sense of guilt without having any responsibility," he adds.

That responsibility fell to McKeich - who picked songs based on how well they'd work with a 60-piece orchestra.

"If we can do it properly then [the audience] might get to hear the interesting sounds, textures, and timbres that an orchestra can provide," he says.

McKeich says choosing the Phoenix Foundation for the orchestral treatment was easy.

"There's space, there's dynamics, some of it's strong and rock, some of it's ballads - there's a mixture."

With the tour visiting Wellington, Auckland, Christchurch, and Dunedin, the band says fans should make every effort to check it out - joking every show after these will be a disappointment.

You can buy tickets for the four shows here.