IT’S the world’s sunniest show - and this summer, for the first time, feelgood musical Mamma Mia! is coming to an open air stage at Harewood House.

Playing to a limited capacity audience from August 13-20, the performances are part of a UK tour celebrating 22 years since Mamma Mia! premiered in London. Audiences can pre-order picnics and visit Harewood House on the day of their booked shows for a discount, enjoying the exhibitions of contemporary art, rare bird garden, and over 100 acres of grounds.

Set to the music of Abba, Mamma Mia! is the tale of a mother, a daughter and three possible dads on a Greek island idyll. Since its West End opening in 1999, the hit show has been turned into two hit films.

But on opening night some theatre pundits were anticipating a flop. “A lot of people doubted us,” says creator and producer Judy Craymer. “The Lion King opened about the same time, and we were very modest by comparison.” She says many people were expecting a kind of Abba tribute show: “They couldn’t get their heads around it. They were asking me who was going to play Frida and Agnetha.”

Even Abba songsmiths Benny Andersson and Björn Ulvaeus had their doubts: They needn’t have worried. Judy, together with writer Catherine Johnson and director Phyllida Lloyd, pulled of a theatrical triumph with cross-generational appeal, delighting Abba’s loyal fans and winning them legions of new ones.

Judy was working in Tim Rice’s production office in the early 1980s when she first conceived the idea. Rice was writing Chess, his collaboration with Andersson and Ulvaeus, and Judy was sent to collect Bjorn from the airport. The pair quickly struck up a friendship. “Chess was a big project, I was flying to Stockholm with Tim every week, working in Benny and Björn’s studio,” says Judy. Crucially, she had access to the Abba pair - “which was very fortunate, because otherwise I’m not sure they would have taken this on” - and re-discovered their music: “I listened to their songs with a different ear. They’re about strong women, they take you on a journey. They spoke to me as theatre songs. You’d be lucky to have two like that in a musical, let alone 20. I started thinking about how to turn them into narrative.”She felt it should be “weddings, holidays, something celebratory, because everyone listens to Abba in a happy moment”.

Judy met Catherine Johnson, who was working on TV’s Band of Gold, who suggested the story of a mother and daughter. “Catherine was a single mum, I only had about £1,000 so I said, ‘I’ll pay you £500 now, and £500 when you’ve written it’,” recalls Judy.

With Phyllida Lloyd on board as director, the trio put together a female-led show full of joy, romance and fierce mother-daughter dynamics; an exuberant comedy set on a Greek island, with a playful nod to family dramas of classical tragedy. It’s a narrative that, says Judy, that sets Mamma Mia! apart: “There’s a structure, properly developed characters and themes. I like to think Mamma Mia! raised the bar.”

It’s universal appeal has seen the show play to packed theatres worldwide. In New York it helped revitalise Broadway after 9/11, proving a tonic for theatre-goers in the traumatised city.

During last year’s lockdown, Judy was busy planning a third Mamma Mia! movie.“I wanted something to cheer us all up!” she laughs. “I think there’s a trilogy there. There are lots of wonderful Abba songs that we haven’t yet mined, and Björn and Benny have written a couple of new ones.” In the meantime, she’s looking forward to Harewood House: “Being outdoors will be perfect. That wonderful feeling that the sun is setting as the show’s starting. And people will be with friends and family. That’s always been key to Mamma Mia! - people come, then they bring kids, granny, grandad. Doing it in the open air is a dream come true.”

l Visit mamma-mia.com or call 0344 338 800.