Nor will their parents, their teachers, and children at nine other primary schools in the Birmingham area who did their own versions of the show.

"Four senior leaders from the school were at the performance and all four were in floods of tears," said Raddlebarn's head teacher Angela Lowry.

"It was magnificent, I was so proud of the children and everyone else involved in a wonderful project - but I felt a bit embarrassed when I had to get up and talk to the parents because I was bright red from crying.

"The buzz in school, and on the gates with parents the morning after the show was just magnificent - some of them were still choked up."

The subject matter of Precious Emily was as far removed as it could be from the world of Disney, computer games, children’s books, popular TV shows and anything else that might usually interest primary school children.

It was all about weightlifting, or more specifically two weightlifters who triumphed against the odds.

The message the show put across to the children, aged eight to 11, was: you can achieve anything if you never give up.

Precious Emily takes its name from two of the heroes of the sport who were born more than half a century apart, 86-year-old Precious McKenzie and Emily Campbell, 28.

The schools were given the biographical details they needed about Precious and Emily, plus the services of a professional director to help them develop their own show, with songs.

What made the Raddlebarn show extra special was the presence on the day of two very special guests: Precious and Emily, one of whom was 55 miles from home and the other 11,300 miles.

Campbell, an inspirational figure who became her nation’s first-ever female medallist in weightlifting at the Olympic Games last year, is from Nottingham.

McKenzie, who became the first athlete in any sport to win four straight gold medals at the Commonwealth Games way back in 1978, has lived in Auckland, New Zealand for nearly 50 years.

He is in Britain visiting family and old friends, and is hoping to present the medals at a weightlifting session during the 2022 Commonwealth Games, which open in Birmingham on July 28.

They were both at the prestigious Midlands Arts Centre in Birmingham last Thursday (July 14) for the final gala performance of Precious Emily, a Birmingham 2022 Festival production that featured the 10 schools that took part in the project, all of which are from disadvantaged or deprived parts of Birmingham.

How did weightlifting manage to get such prominence as part of the Birmingham Festival - "the biggest celebration of creativity ever in the region, and one of the largest ever Commonwealth Games cultural programmes"?

The man with the answers is James Yarker, creative director of the theatre company Stan’s Cafe.

He has form when it comes to choosing unusual topics for school performances, having created a successful project about the Cuban Missile Crisis - the 1962 US-Soviet Union standoff that led the world to the brink of nuclear war.

"We were looking for the next unusual choice for a big project," he said. "Precious Emily is it."

The Birmingham 2022 Festival is a well-funded cultural extravaganza that "is committed to being open and honest, even about the most uncomfortable of topics".

Racial discrimination, hopeless parenting, a lack of education, being told "you’ll never make it" or being criticised for your size - between them McKenzie and Campbell could raise a few "uncomfortable topics".

Yarker had been to watch weightlifting at the London 2012 Olympic Games because of his childhood memories, and was hooked.

He also went to the British Championships in nearby Derby in January.

He had "a really strong memory of seeing Precious on Blue Peter when I was a boy and being totally captivated by this guy.

"He was no taller than me, 4ft 10in (1.47m) but he was incredibly strong.

"I thought, there’s no reason why kids today won’t feel the same way about people who are amazingly strong."

"I didn’t want it to be a totally historical show so we wanted to contact a current lifter and Jo Calvino, the Birmingham 2022 weightlifting competition manager, suggested Emily Campbell - and this is long before Emily won her medal in Tokyo.

"We have a woman in the heaviest weight class and a 4ft10in man from the lightest - a great contrast.

"Also it helps that Emily’s dad is from Jamaica, her mum from England.

"When we presented the idea to the Festival people they absolutely lapped it up."

There is much more to the life stories of McKenzie and Campbell than lifting weights.

Yarker has read a lot about McKenzie, in a 2013 book about the Commonwealth Games and a 1975 biography.

His birth in Durban in South Africa was not recorded because he was "coloured”.

When he was still infant his father was killed by a crocodile, leaving his alcoholic mother impoverished and unable to care for Precious and his sister Gloria.

The young siblings lived on the streets of Pietermaritzburg, were frequently abused by a string of foster parents - one women scarred Precious for life in a knife attack - and were illiterate until their teenage years.

Being forced to carry four-gallon drums of water when they were tiny children may have stunted their growth; their elder brother grew to 6ft (1.83m).

Eventually they were taken in by a remote Catholic mission where they received an education and, for McKenzie, encouragement in his training in gymnastics and acrobatics.

McKenzie came close to horrific death while at the mission - he was within inches of drowning in human excrement when he fell into a cesspit and was sucked down inch by inch.

"What a death that would have been! Worse than my father. Can you possibly imagine anything worse?"

He grabbed a strong tuft of grass at the edge of the pit and was pulled out by other boys.

When he took up weightlifting at a gym in Pietermaritzburg, aged 17, it soon became clear that he was a phenomenal talent.

But being the national champion at bantamweight, the best weightlifter in South Africa, counted for nothing in an apartheid regime. Not only was he overlooked for Commonwealth Games and Olympic teams, he was told he could not lift on the same platform as whites, could not travel with them, could not wear the same uniform.

McKenzie and his young family escaped to Britain, and his first Commonwealth Games gold medal came for England in 1966 in Kingston, Jamaica, where he famously asked Princess Anne for a dance at the post-Games party, starting a lifelong relationship with the Royal Family.

He won again in 1970 and 1974, gaining an army of fans along the way as he featured in newspapers and on television, most notably when he lifted Muhammad Ali on his shoulders at a charity dinner in London.

McKenzie was so popular in New Zealand, where he won his third Commonwealth gold in 1974, that he moved there, and in 1978 he was competing as a Kiwi when won that record-breaking fourth gold medal in Edmonton, Canada.

The Queen, who had invited McKenzie and his wife to Buckingham Palace before, made sure she was there to see it - and sent an urgent invitation to him to attend her garden party in Edmonton the next day.

McKenzie worked in Auckland for many years as a specialist in preventing back injuries, and even now he intends to lead an exercise class for the over-80s on his return to New Zealand.

When he visited Birmingham last month to watch the Raddlebarn show, the children were unaware he would be there until the last moment. When he came in he won over the children immediately by putting a folded leaf in his mouth and making bird noises.

"They absolutely loved that," said Yarker, who wrote a 5,000-word story of McKenzie’s life that was used as the basis for the Precious part of the show and adapted school by school.

"And Precious clearly loved the fact that there was a show about him, about his life."

McKenzie concurred: "What a surprise it was - one of the biggest honours I have had."

Campbell, too, has clearly enjoyed herself, having visited all 10 schools.

"It’s been ridiculous, the kids are so enthralled," said Yarker. Often the whole school is there, not just the class doing the show.

"Emily is amazing with kids. She devised a little quiz that engaged them, brought in some flags and asked them to identify the countries. They were the places where she had competed or trained.

"She took her medals to the schools and the children loved to see them and even more to touch them.

"We’d play a video of her medal-winning clean and jerk from Tokyo, and I just about welled up every time."

Campbell was working full-time, in pastoral care for children with special education needs, when she started competing for England four years ago.

Now she is a full-time weightlifter - with plans for the future.

In an interview for insidethegames after her return from Tokyo, Campbell spoke of her dream of setting up a company to take weightlifting into schools, especially in socially deprived areas.

"It means the world to me to inspire kids."

When it comes to parents, and support from her family and the local community, Campbell is the polar opposite of Mckenzie, having spoken glowingly of their role in her success.

But discrimination is a common theme for both weightlifters. 

In an interview last year Campbell spoke of racism, of attitudes among the white population that black people in Britain "come from lower class, from lower money".

Head teacher Lowry said, "The messages in the story, the challenges both Precious and Emily had to face, they’re very real in this day and age unfortunately.

"Despite all those challenges they never gave up, they came through.

"The messages from that were just fantastic - a real mind-opener for the children and some of the parents as well.

"People told Emily she couldn’t do this, it wasn’t for her, she was making bad choices, she’d be a laughing stock - and there she is winning an Olympic medal.

"How must she feel? I can’t imagine that amount of pride, doing something everybody told her she couldn’t do.

"She made it sound so achievable, it made the children feel that anything was possible.

"There are children who can be a bit shy and because so many had a turn in the show at being Emily or Precious, some of them came out of their shell in a way you’ve never seen before. It was just brilliant.

"The parents were unsure at the start but there were tears in the audience at the performance.

"Emily is so brilliant with children, I said to her, 'Do you want a job? If ever weightlifting doesn’t work out for you, don’t forget us.'"

Yarker said, "Emily has said some good things about unhelpful comments from others, about sleep, nutrition, diet, and has talked about the importance of mental approach - if you think you might not be able to lift it, you won’t lift it."

Unlike McKenzie, Campbell has not yet won a Commonwealth Games gold medal - but it will be a big surprise if she is not on top of the podium for England this year, after her record-breaking effort in Tokyo.

"Nobody had really heard of her back when the project started, unless they were in the weightlifting world," said Calvino, who lifted for Britain at the World Championships.

"As soon as James had made one phone call to Emily he said, 'I absolutely love this girl!' - and he was blown away by her journey in the sport.

"What Emily did in Tokyo has really catapulted the project.

"Emily is the right fit for this - she's from the Midlands, everyone loves her, she's great with kids, she loves dance and used to be in a dance group, she's a big girl, different to the petit ones you normally associate with sport, and she understands the demographics, the communities they're trying to reach with this project.

"Weightlifting is so important in the Commonwealth, not just the lifting but the diversity within the sport.

"Birmingham is a great city to put on Precious Emily because it's so diverse.

"Precious is such an important part of the history of weightlifting in the Commonwealth Games too - and so many people remember seeing him on television, or their parents were fans of his.

"What a good way to promote the future of the sport."

Some of Campbell’s national team-mates have visited the schools too, to teach weightlifting technique, and some of the children lift wooden discs during the show.

Stuart Martin, Britain’s head of performance, helped out, as did Commonwealth Games athletes Noorin Gulam and Chris Murray, along with Jenny Tong and others.

"The children are at an age when some are beginning to understand their bodies in space, how they work," said Yarker.

"Some are strong enough to lift regardless of technique, some can do it only when they have the technique right, some are all at sea.

"It was instructive that some wanted to stay behind and learn more."

That will be good news for Campbell’s coach, Cyril Martin, who is very keen for British Weight Lifting to focus more on development, on recruiting young lifters.

"Things are changing for the better, and Emily is playing a big part in that," said Martin, whose gym is also in the Midlands, in Alfreton.

"Emily is very busy but she makes the time to be treasurer for the kids at our gym and they all know her and look up to her - she’s like a mother to some of the younger ones and it’s great to see.

"She’s been to a lot of schools too, encouraging them to try weightlifting.

"She couldn’t do any more.

"Emily’s medal makes so much difference - it’s what we needed.

"Now British Weight Lifting is looking at development rather than just expecting people to appear from nowhere, which was the case in the past.

"I was pulling my hair out at times, especially around the time of the Manchester 2002 Commonwealth Games when it was obvious that some of our best lifters would retire.

"You have to develop lifters."

There are 500 young children in Birmingham who now know a lot more about weightlifting than they did a year or two ago, and with a Commonwealth games legacy funding boost to support clubs in the area, it could be a productive area.

They will be watching when Campbell goes for gold on August 3, as will their head teacher Lowry.

There are plans for 20 children to sing one of the songs from Precious Emily in the pre-session entertainment before Campbell lifts.

"And when they’re older they’ll tell their own children, 'I remember doing a project called Precious Emily'," Lowry said.

"They’ll always keep that with them, they’ll remember it all their lives."