ABBA Surprises Audience by Appearing during the 20th 'Mamma Mia' Anniversary Celebration

Leading men Benny Andersson and Bjorn Ulvaeus from Swedish pop group ABBA made a surprise appearance as their hit number “Mamma Mia!” celebrated its 20th anniversary in London’s West End.

The duo was welcomed by huge applause by the crowd at Novello Theatre in London. Thanking the audience for being “fantastic”, Ulvaeus told the crowd it was “both strange and wonderful” to be on the stage.

A medley of ABBA classics including “Waterloo” and “Dancing Queen” played as confetti rained down of theatergoers. An ecstatic Andersson praised the cast, calling them “wonderful”.

“There is a chance to be immersed, to get moved and I was tonight and I'm happy that I can feel that."

Andersson also shared how it had been a long time since he had seen the show, adding he felt “moved” on the anniversary.

Ulvaeus and Andersson, who have previously appeared at anniversary performances, were joined by producer Judy Craymer, writer Catherine Johnson, and Phyllida Lloyd. Ulvaeus lovingly described the trio as “three angles.”

The tale is centered on a mother, a daughter, and three possible fathers on a peaceful Greek island and unfolds to ABBA’s timeless pop numbers. Over nine million people have seen the stage show at three different venues in London.

Originally opened at the capital’s Prince Edward Theatre on 6 April 1999, the London stage show has been seen by over nine million people and played over 8,000 performances. The show transferred to the Prince of Wales theatre in 2004. The musical has grossed more than four billion dollars at the box office.

The musical was adapted into a movie in 2008 before its stars Amanda Seyfried, Meryl Streep, Colin Firth, and Pierce Brosnan reunited for a sequel “Mamma Mia! Here We Go Again” in 2018.

ABBA announced last year that they have recorded their first music in 35 years. Reports suggest the music will be released later this year.