Mamma Mia, here they go again! Abba announces virtual concert, 1st new album in 40 years

Swedish superstar group Abba announced Thursday they are releasing a new album, Voyage, and will "perform" a concert — as digital characters — in London's Queen Elizabeth Olympic Park.

Band members Björn Ulvaeus and Benny Andersson made the announcement in person on Thursday at the park's ArcelorMittal Orbit sculpture.

The Abba Arena, a new purpose-built venue that can hold 3,000 audience members, is being built at the park to host the group's upcoming concert.

The announcement was broadcast on a YouTube livestream event, which saw more than 200,000 people tune in around the world.

WATCH | Abba announcement awes fans:

The livestream on Abba's official YouTube channel began with a new song, I Still Have Faith In You, sung by the band's avatars, also known as Abba-tars.

The group created social media channels specifically for the Abba Voyage project last week. Fans were told to join Abba at abbavoyage.com, where they could register to be the "first in line" to hear more about the project.

On Tuesday, the band posted another teaser on Twitter encouraging fans to join them at 5:45 p.m. U.K. time Thursday to be part of a "historic" event.

"The journey is about to begin," the tweet said.

'Abba-tars' will perform new and old songs

The Swedish pop group — made up of Agnetha Fältskog, Björn Ulvaeus, Benny Andersson and Anni-Frid Lyngstad — is best known for hit singles like Dancing Queen and The Winner Takes It All, which were adapted for the musical Mamma Mia! in 1999.

Although the quartet won't appear on-stage for their concert, they will appear as digitized versions of their younger selves. These 'Abba-tars' were created by George Lucas' international effects facility, Industrial Light & Magic (ILM).

The idea for the concert has been in the works since 2016.

"We wanted to do it before we are dead," laughed Andersson.

The band decided it was too complicated for them to perform live, but they still wanted to perform somehow.

"With the help of our younger selves, we travel into the future," Andersson explained.

The concert, slated for 2022, has a setlist of 22 songs, including classic hits like Dancing Queen. 

The band will also perform new music, including songs I Still Have Faith In You and Don't Shut Me Down, which were made available to the public today.

Abba's road to reuniting

Getting back together to record their new music brought back wonderful memories, said Andersson. Both he and Ulvaeus said they wished Fältskog and Lyngstad had been able to join them for Thursday's announcement.

Gary Collins of the Official International ABBA Fan Club suggested it was the band's chemistry that made them want to reunite, record new music and go "on tour" after so many years. 

"I think they found they rather missed being with each other," he said.

Since performing their song Waterloo at the Eurovision Song Contest in Brighton, England, in 1974, Abba is estimated to have sold almost 400 million singles and albums across the world.

The band, which initially consisted of two married couples, split in 1983 after marriage breakups between Ulvaeus and Faltskog, and Lyngstad and Andersson. 

Around a decade after disbanding, the group released ABBA GOLD: Greatest Hits in 1992, which became a worldwide bestseller. 

In 2016, the group celebrated Abba's 50th anniversary by performing on stage together for the first time in 30 years. The last time the band was seen together prior to that performance was during the launch of the film Mamma Mia! in 2008.

The band announced that they had recorded two new songs, I Still Have Faith In You and Don't Shut Me Down, in 2018, their first recorded material in 35 years. 

Concert tickets will go on sale on Sept. 7 and their new album will be released in November.