The AbbaWorld museum and theme park opened in Earl's Court London on Tuesday amid a flurry of spangled jumpsuits and cheesy yet catchy harmonies.
Two of the original line-up appeared on stage - Bjorn Ulvaeus and Anni-Frid Lyngstad.
"http://www.youtube.com/v/c83Rsp9mjlE&hl=en_GB&fs=1&"
"Me and Bjorn sang two of our songs downstairs. It wasn't quite like before, but it was okay," said Lyngstad.
Ulvaeus, looking professorial and serious in spectacles and beard, reminded the crowd how successful the supergroup was in its time. "Can you imagine 375m CDs? I can't."
Of the exhibition, he remarked: "We feel like pioneers again, like we did when we did Mamma Mia (on stage)."
The exhibition tells the band's story in 25 rooms spread over 2 800 square metres with karaoke booths, gold discs and video installations.
In what promises to be one of the most exciting and spectacular features of the exhibition, the audience will be able to sing and dance together with a holographic illusion of the supergroup.
And what was Boy George's favourite bit of the show: "Definitely the costumes. I was a punk when they were around, so I hated them, but I love them now, especially the clothes. I wish the whole exhibition had been clothes." - IOL and The Independent