They are connected by their country of origin and their international success: Björn Ulvaeus, member of the Sweden's most successful band, ABBA, is adapting a story from arguably Sweden's most popular children's book series, Pippi Longstocking, into a musical.

"Pippi at the Circus" celebrates its premiere at the Cirkus venue in Stockholm, on July 12.

The circus musical is based on Astrid Lindgren's short story from the late 1960s. "I grew up with it," said Ulvaeus, who was raised just 70 kilometers (43 miles) from Astrid Lindgren's hometown of Vimmerby, about Pippi's adventure.

The first Pippi Longstocking volume was published in 1945, just months after Björn Ulvaeus was born.

The musical was originally due to premiere in 2020 — on the 75th anniversary of Lindgren's first work. The pandemic thwarted those plans.

In "Pippi at the Circus," Tommy and Annika pick up their friend Pippi to go to the circus. Pippi has no idea what a circus is supposed to be, but is so enthusiastic about the performance that she quickly climbs into the ring herself and turns the performance upside down.

The 77-year-old Ulvaeus worked on the show with ABBA colleague Benny Andersson, who recorded songs with his own band, Benny Anderssons orkester. Ulvaeus wrote the lyrics. The result was a colorful mix in which "everything fits together, everything has a circus element," says Ulvaeus.

Originally used as a circus, Stockholm's Cirkus arena opened in 1892 and is today mostly used for concerts and musical shows. Björn Ulvaeus wanted to find a way to avoid having the venue go unused during the summer months: "It's such a waste and stupid because up to 15 million tourists come to the city every year," he said at a press presentation in May.

He thought about what could appeal to families and children in the summer, something that is renowned; As a Swedish, global brand, Pippi's circus story was a clear-cut choice for the project.

The ABBA star sees Pippi as a symbol of empowerment for girls and women: "I like her civil disobedience, curiosity and strong will," Ulvaeus said.

Last year ABBA made a surprise comeback after almost 40 years with their album, "Voyage."

In May, the accompanying show was launched in a specially built ABBA Arena in London's Olympic Park. Accompanied by a live band of 10 musicians, the four members of the Swedish band — Agnetha, Anni-Frid, Benny and Björn — appear as digital avatars, or ABBAtars.