Now, however, a packed audience gazes on a scarlet-swathed stage, having even less of a clue what to expect. When a band clad in golden robes enters, it is not the surviving members of Sun Ra's Arkestra, who will close the festival the next night wearing similarly sparkly apparel. Sporting a shimmering gold lame leotard, the young woman at the centre of the spectacle looks as showbiz as it gets.
As she and her entourage open with a version of Laura Palmer's Theme from David Lynch's cult TV show, Twin Peaks, one could be forgiven for presuming that Club Silencio, the mysterious nightclub in Lynch's film, Mulholland Drive, had set up shop in Pontin's. The selection of equally tasteful cover versions of songs by the likes of Nine Inch Nails, Sugababes and Super Furry Animals that follows, each introduced with language as colourful as a Tiger Bay sailor on shore leave, suggests otherwise.
Mid-way through, Joy Division's Love Will Tear Us Apart builds from an acoustic ballad to something that sounds akin to Shirley Bassey fronting Nirvana. This is not only the most avant-garde moment of the entire festival. In its jaw-dropping brilliance, it is possibly the most expectation-confounding musical moment ever.
The woman onstage is Charlotte Church, the former child star who once sang for the pope, took on Rupert Murdoch at the Leveson Inquiry, and who has become an anti-austerity icon. As the gold lame leotard hints at too, Church is also ringmistress of her own destiny, and this is her Late-Night Pop Dungeon.
Next week, Church brings her ten-piece Pop Dungeon band to Edinburgh to headline Celts, the latest genre-busting extravaganza from spoken-word cabaret night Neu! Reekie! Designed to tie in with the National Museum of Scotland's current exhibition of the same name, if Church's ATP appearance is anything to go by, Edinburgh is unlikely to know what's hit it.
“I just wanted to do something fun,” Church says of the roots of her Late Night Pop Dungeon. “Looking at the political situation and how down my lefty friends were, I thought it would be good to do something that was really up. I didn't really have much new stuff on the go, so we thought we'd just go for it. We've done it three times now, and we've changed it every time. We have songs dropping into other songs, so when we do En Vogue's Don't Let Go, at one point it goes into 21st century Schizoid Man by King Crimson.
“Also, for quite a long time I'd said no to everything, partly because I didn't want to confuse people anymore, because I've had quite a few metamorphoses, which is just the way things have gone, and also because I just wanted to be a mum. Now, I've started saying yes to things I might have been scared of before, and as a result, my career and my life are now more varied and more rich than ever before.”
In this respect, thirty-year old Church is en route to becoming a full-on twenty-first century renaissance woman. This year alone, as well as taking the Late Night Pop Dungeon to Glastonbury, where the previous year she'd interviewed Russian female punk provocateurs Pussy Riot, Church took part in the inaugural Festival of Voice at Cardiff's Millennium Centre. As well as singing alongside former Velvet Underground co-pilot John Cale, she took the title role in The Last Mermaid, a music theatre reimagining of Hans Christian Anderson's The Little Mermaid, which she co-created with composer Sion Trefor and songwriter, Pop Dungeon guitarist and life partner Jonathan Powell.
To trail the festival, Church presented an edition of BBC 2's arts magazine show, Artsnight, interviewing Laura Mvula and Welsh alt-pop singer Gwenno as well as looking at a choir project instigated by the National Theatre of Wales.
“We talked about voicelessness,” Church says of The Last Mermaid, “and the show came out of that. I worked on it with an intensity like I've never done before, but I'm not sure theatre's for me. I'm not very good at repetition. I'm more of a flitter. I was absolutely banjaxed by the end of it, so I'm in no rush to do theatre again.”
That Church boxed off such a varied itinerary at all is testament to her polymathic talents. That she did it without either a manager or agent speaks volumes about how much she stands apart from the celebrity treadmill in a wilfully singular fashion.
“I don't have any people,” she jokes. “I'm my own manager, but because things are going so well just now, that's getting quite difficult.”
An example of this comes the day we're originally supposed to talk. Church's phone keeps ringing out, until eventually she texts to apologise, but she completely forgot that we'd arranged the interview, and she was at the cinema with her two kids.
Even so, Church answers all email inquiries herself, responding to whatever interests her. This was the case with Neu! Reekie!when she was first approached by the event's organiser and co-host, Michael Pedersen.
“Michael's language was so flowery and descriptive,” she says, “and it really caught my eye.”
For someone who was a victim of the News of the World phone hacking scandal, such openness is a risky strategy, though it hasn't stopped her addressing anti-austerity marches, showing public support for Labour Party leader Jeremy Corbyn and frothing with frustrated rage on social media following the Brexit referendum result. After being vilified by the tabloid press, however, Church is way beyond caring what people think.
“I'd learnt my craft and sung around the world with orchestras,” she says. “I had my credentials, but I was being portrayed in the tabloids as this ladette chav slag. That annoyed me, because it wasn't accurate, but I felt powerless against it.”
In her statement following an out of court settlement with the News of the World, Church declared that those behind the hacking weren't sorry, but 'only sorry they got caught.'
“The fact that absolutely none of the recommendations made at the Leveson inquiry have been taken up is a bit of a shame,” she says flatly.
If Leveson marked the beginning of Church's politicisation, she remains unrepentant in giving voice to her views.
“If people disagree with me,” she says, “then what of it at the end of the day? Some people don't agree with me and explain their point quite eloquently, other people completely attack me, but it's really water off a duck's back to me. The world is such a fucked up place just now. There's so much propaganda, and so much misinformation about things being put out, that you have to keep questioning it. I won't stop campaigning until we find some kind of way through it.”
In terms of her artistic future, Church plans to release an album, “collaborating with as many people as I can.”
There is the possibility of a TV comedy, although again this will be on Church's terms.
“I've no interest in doing scripted comedy,” she says. “I did a couple of pilots for the BBC which I think were quite sparky, but for me something that's funny has to be super super open. Basically I'm a lazy bitch who doesn't want to have to learn any lines,” she laughs.
One other long-cherished project remains in limbo.
“I've been trying to make a documentary on education for years,” she says, “but the BBC aren't having any of it.”
Church talks about Sir Kenneth Robinson, the influential educationalist whose ideas focus not on traditional exam-based achievements, but on using learning to awaken creativity.
“It's so simple,” Church enthuses, “this idea that schooling can be some kind of individual revolution. The effect these things take on human beings is in childhood, when you most have the ability to take things in and be creative. The way we're doing it just now for these gorgeous little kids is so antiquated.”
As for the Pop Dungeon, Church wants it to remain “a little gem. I'll do bits and bobs with it, but I don't want it to be a cash cow. I want to just keep it light and constantly keep reworking it, so it remains a special thing for everyone involved.”
This is a mantra for everything she gets involved in.
“In my life and work I just follow my nose,” she says. “I've been really lucky in the last couple of years to have had such fantastic opportunities, and that, coupled with my new approach of positive action, has really helped make things happen. Right now, I'm all about just saying yes.”
Charlotte Church's Late Night Pop Dungeon plays Neu! Reekie! - Celts, with Ette, Liz Lochhead, Lyre, Loki and Becci Wallace, Lomond Campbell at the National Museum of Scotland, Edinburgh, September 23.
The Herald, September 23rd 2016