But Faltskog is back. This week she's releasing a new solo album called "A." It is the 63-year-old's first album since 2004's "My Colouring Book," which, at the time, she assumed would be her last release.
"I'm also that kind of person that I don't want to close any doors," Faltskog said in a recent interview from London. "So when this opportunity came up to do another one, I just couldn't say no."
Credit producer Jorgen Elofsson (Britney Spears, Kelly Clarkson) for getting Faltskog back in the studio. She said all it took was hearing demos of the album's first three songs, including the first single, the '80s synth-pop ballad "When You Really Loved Someone."
The album title was suggested by Elofsson, in part as a nod to Faltskog's first name and also to ABBA. The album is crammed with ballads custom-built for Faltskog's strong soprano, boasting the sort of lyrics the singer is known for: songs about the sensitive, complicated nature of relationships.
While the material covered familiar ground, Faltskog feared she was vocally "rusty" and actually consulted with a coach twice.
"I found I was getting tired easily. And I wanted to find that old feeling when you work with the stomach muscles. Suddenly, it was there."
Faltskog said she no longer lunges toward her radio preset buttons at the first strains of ABBA's Top 40 evergreens such as "SOS," "Take a Chance on Me" and "The Winner Takes It All."
"And now when [the music] comes back, [I remember] the hard work behind it," she said. "The quality was very good."
ABBA, which included Anni-Frid Lyngstad-Reuss, Benny Andersson and Bjorn Ulvaeus (Faltskog's ex-husband), has sold more than 300 million albums worldwide.
While there aren't plans to reunite, Faltskog said band members keep in touch.
"I met Frida last summer on vacation, and we got very nostalgic," she recalled. "And Bjorn and I see each other rather often with the children and grandchildren."