The Abba musical Mamma Mia!, which celebrates its fifth anniversary on Tuesday, is well on its way to being one of the most successful stage shows in history.
By Neil Smith
BBC News Online
Three million people have seen the original London production, and a further 14 million have seen it around the world.
Mamma Mia! opened in London in 1999 (photo by Catherine Ashmore)
In West End terms the show is a relative newcomer, lagging some way behind Les Miserables (now in its 18th year) and The Phantom of the Opera, which celebrated its 7,000th performance in the capital last August.
However, Abba's international popularity has made the musical easy to export to other countries.
The show is currently running in New York, Las Vegas, Toronto, Tokyo, Seoul, Hamburg and the Dutch city of Utrecht.
Further productions are planned in Spain, Sweden and China - and that does not include the versions currently touring America and Australasia.
The musical generates $8m (£4.4m) a week in ticket sales and has made more than $750 million (£412m) at the box office.
Hard to believe, then, that the notion of a musical featuring songs from Abba's back catalogue was originally considered a risky proposition.
"We really had no idea how it was going to be received," says producer Judy Craymer on the show's official website.
"I knew from the outset that Mamma Mia! had to be much more than just an Abba compilation or tribute show."
To that end, playwright Catherine Johnson was commissioned to write an original script that incorporated the songs within a coherent storyline.
The show is set on a Greek island (photo by Catherine Ashmore)
Set on a small Greek island, the musical tells of a young woman, Sophie, and her fiercely independent mother, Donna.
Sophie, who is about to be married, has secretly invited three of her mother's former lovers to her wedding in the hope of discovering which of them is her biological father.
"It was very important that I created believable characters and gave them all a true storyline," says Johnson on the Mamma Mia! website.
"I absolutely worked to get the story and the songs to work together."
Although Abba are not mentioned by name, many of their songs are featured - among them The Winner Takes It All, Super Trouper, Gimme! Gimme! Gimme! and Money, Money, Money.
The latter is particularly apt as both Johnson and Craymer - along with the show's original director Phyllida Lloyd - have been made millionaires by its worldwide success.
That success was not guaranteed, however. The show opened on Broadway a month after the 9/11 terrorist attacks, at a time when falling ticket sales forced many other shows to close.
Mamma Mia! takes its title and score from the songs of ABBA
Luckily Mamma Mia! already had a $30m (£16.5m) box office advance, so the musical opened as planned.
Last month it celebrated its 1,000th performance at New York's Cadillac Winter Garden Theatre - formerly the home of Andrew Lloyd Webber's Cats.
Tuesday's fifth anniversary performance at London's Prince Edward Theatre coincides with the 30th anniversary of Abba's Eurovision Song Contest win with Waterloo.
Songwriters Bjorn Ulvaeus and Benny Andersson are scheduled to attend, and there are unconfirmed rumours they will be joined on stage by former bandmates Agnetha Faltskog and Anni-Frid Lyngstad.
If so, it will mark Abba's first official reunion since the legendary band broke up in the early 1980s.
However, the Scandinavian supergroup did reform briefly last year - to sing for a friend at her private birthday party.