We all know everything there is to know about Abba, right? Yes, both couples got divorced, but they were friends to the end, just happy to create music that made the whole world sing and sway awkwardly on unfeasibly high platform shoes. Carl Magnus Palm realised that wasn’t the full story, and the Stockholm-based writer decided to delve deeper than the smiles in the photos. Bright Lights, Dark Shadows: The Real Story of Abba (Omnibus Press, $55) may have a naff title, but the story contained within takes some unusual twists. "They were normal people with normal problems," says Palm, 36. "But the media preferred to portray them as a safe family group made up of two happy couples."

There are plenty of anecdotes that jar with the image (who knew that Björn wrote the words to "The Winner Takes It All" while he was drunk on whisky?), plus details of bitter arguments with their controlling, alcoholic manager, and the cracks that emerged in their own relationships. Frida’s family background is strange (she thought her father was dead until she met him in 1977), and later her daugher and third husband died witihin two years of each other. As for Agnetha, the quips about her having the sexiest bottom in Europe were the least of her problems: she constantly missed her children while on tour, she had traumatic travelling experiences, and her romances floundered after the divorce from Björn. Then she became a recluse, only to enter into a relationship with an unstable fan who stalked her.

Today, Palm’s life is entwined with the Swedish foursome. He wrote Abba: The Complete Recording Sessions, penned the liner notes to compilations and re-releases, and collaborated on the book From Abba to Mamma Mia! So it’s strange to discover that until 1980, the only Abba record he owned was the 1973 single "Ring Ring."

"I liked them, but I think I hid the fact from myself," says Palm, whose favourite band is the Beatles. "I even teased friends who were fans. In Sweden there was this left-wing cultural climate in the ’70s that was very judgmental. If something sold 500,000 copies it was crap and if it sold two copies it was wonderful. But secretly I loved Abba."

Barry Divola