It has to be one of Stan Walker's best performances yet - and all he's wearing is a grass skirt. He's up there on stage singing in his typically soulful lilt, but his band, Small Axe, who also wear their piupiu with an odd mix of pride and self-consciousness, are playing a lively, skanking reggae-meets-Maori showband tune.
It's not the sort of song you expect to hear the former Australian Idol winner and pop star singing. Because this is no TV talent show or a video for one of his catchy and suave chart-topping hits. This is a scene from Walker's first feature film, Mt Zion, in which he plays Turei, a young potato-picking Maori fella from Pukekohe with dreams of being a singing star.
You see, it's 1979 and Turei and his band - made up of older brother and guitarist Hone (Troy Kingi), and best mates Reggie (David Wikaira Paul, best known perhaps as Tama from Shortland Street) on bass, and Pou (Darcy-Ray Flavell-Hudson) on drums - are taking part in the biggest audition of their lives.
If they can convince the gruff and sceptical concert promoter that they are good enough, they have a chance of opening for Bob Marley at his concert at Western Springs in Auckland.
The song they're playing is called Mt Zion and they botch it at the beginning and have to start again. But once Hone's guitar (Kingi is a real-life guitar supremo) kicks in, the song starts to simmer and leaves you shaking, skanking, and singing along.
"The song was probably never intended to be played fast like that," ponders Walker, talking on the phone from his home on the Gold Coast, "but what made it come out like that [in the film] is because Hone is rushing to get home, he wants to get out of there because we're wearing our piupiu and all that. He just wants to get back to Pukekohe. So everything goes a little bit faster than it should have done," he says, as if their performance was a real audition.
For the record, Turei and the boys are shortlisted for the support slot alongside a band called Golden Harvest (yes, the real-life band who played before Marley that year).
It's a feel-good, fun scene and the point where the film truly takes off - or, as writer and director Tearepa Kahi, puts it: "That's the moment where the roller coaster really goes into high gear."
Because, although Turei has talent, his "Papa" (played by Temuera Morrison) and mother just want him to knuckle down and pick spuds. But he has other ideas and is prepared to do - almost - anything to fulfil his ambition to play before his idol.
"Turei is a passionate fella," says Walker. "He does love his family, and he has a really good heart. His intentions are good, but the way he goes about things is not the best."
While Mt Zion centres on his musical quest, for Walker it's also a coming-of-age story about the relationship between a father and his son. "And," says Walker, "the unspoken love between a father and a son. Because every day [for Turei and his dad] it's get up, have a feed, let's go to work. They don't talk about what's happening in each other's lives.
"But," he adds with a laugh, "the film is also about the music - and Bob."
It's going to be a big year for Walker, who will also be one of the judges on TV talent quest The X Factor New Zealand. That show is about something he knows well, but his transformation from singer to actor was a challenge.
It involved a mix of basic acting classes, guidance from Kahi, some expert advice from Morrison - "Tem told me not to act; just be in the moment" - and allowing himself to open up and let go.
"It's hard to explain, and it ended up being quite natural, but initially I was really shy," he says. "But once I felt comfortable I just opened up and it happened naturally."
The casting of Walker was Kahi's idea and it first came to him almost four years ago, after seeing a clip of Walker singing Prince's Purple Rain on Australian Idol.
"I remember thinking, 'What a big-anthem voice'. That was an international voice, right there," he says.
But because Turei's story was inspired by Kahi's own upbringing, the director also wanted an actor who could relate to the character's predicament.
Given Walker's own tough childhood - where he was exposed to drugs, domestic violence and hardship - before his rise to music-star status, he fitted the role perfectly.
Kahi: "I really did think, if we could speak to not just Stan Walker, the pop idol; but Stan Walker, Mum's little boy, then we might have a shot at unlocking something. Because sometimes there's nothing worse than a performer trying to act, because they can't wipe away the performance aspect."
Mt Zion is Kahi's first feature film following a number of TV documentaries and short films, including 2007's Taua. He and guitarist and composer Shane McLean also wrote a number of original songs, including Mt Zion, for the film.
The step up in scale was challenging, but it was nothing compared to what he faced when it came to opening up about his own feelings and telling his own story through Turei. "When you look in the mirror, sometimes it can be quite confrontational," he says. "And with my story and my dad's story, getting honest with it is what you're looking for as the years go by, and the courage to confront all that."
But this is no Once Were Warriors-type family drama, even though Morrison's Papa is staunch and vents his rage on occasion, because instead of "fireworks" and shock value, Kahi's story is "based right here in the home".
"It's a simple little story and we worked really hard on keeping it genuine and sincere."
There are some lovely touches in the film, like the wheelchair-bound koro trundling around the neighbourhood doing a collection for Turei's family after his father injures himself ("People did look after each other in the days before ACC"), and the scenes of Turei and his mates cooling off in the water tower "Everywhere you go in Puke you're bound to see a water tower. We used them to create a space for the bros to speak openly with each other," Kahi says.
And even though he died in 1981, Mt Zion also stars Bob Marley. Explaining how would spoil the film, but let's just say he looks pretty happy to be in Aotearoa.
"So much of the film really happened. I really did lean back on a lot of memory," says Kahi.
That lends it a very personal tone, and he admits he made it with his whanau and iwi in mind.
"I wasn't actually thinking beyond these shores, or beyond Pukekohe," he laughs.
"But then, as the story grew, and the themes became more evolved, I realised there are no borders. This story can speak beyond this place."
BLOWN AWAY BY BOB
Bob Marley played his first and only New Zealand concert at Western Springs on April 16, 1979, as part of his Babylon By Bus tour.
By all accounts the crowd was a diverse mix of white middle-class reggae fans, gang members and Maori - for whom the concert struck a particularly poignant note - including musician Che Fu, who was 5 at the time of the gig.
The set opened with Positive Vibration, and also included hits such as I Shot the Sheriff, Lively Up Yourself, and Get Up, Stand Up.
Of Marley's on-stage presence, The Listener's Gordon Campbell wrote: "He is a dynamic figure to watch - he tightens up, hands clenching and curling above his head, driving the lyrics home. And then he explodes, spinning across the stage in a reeling whirl of limbs and flying hair. His eyes are closed for almost the entire 80 minutes. It's doubtful he even saw the Black Power flag unfurl in front of the stage."
While Marley was here, he also did an interview with the late music journalist Dylan Taite. After Taite broke the ice with the famously guarded Marley by playing soccer with him and his crew, the reggae great gave one of his most candid and best interviews.
This interview and other footage from his visit provided much of Mt Zion director Tearepa Kahi's inspiration for the film, especially the images of Marley's powhiri at the White Heron Lodge in Parnell.
"I'd never seen this footage before and I remember feeling absolutely mesmerised by this moment. The kaiwero coming forward and laying down the wero for Bob Marley, Bob Marley slowly bending down and picking it up. I just thought: 'What would it be like doing the wero to Bob Marley?'."
What: Mt Zion
Who: Stan Walker, as spud-picking singer Turei, and writer/director Tearepa Kahi
Opens: In cinemas, Waitangi Day, February 6
Live chat: Join Stan Walker for a live chat next Thursday on NZ Herald Online