For most of the last three decades, ABBA was but a memory for Agnetha Faltskog. She made concerted efforts to leave behind her past as one of two principal singers of the best-selling 1970s Swedish quartet, best known for the pop classic "Dancing Queen."

"There was several years after I had stopped with the group that I couldn't listen to the music," Faltskog said.

Once the group stopped recording in 1982, and her post-ABBA solo career slowed to a crawl, she happily stepped out of the limelight and settled into domestic life on a small Swedish island near Stockholm. She did just a handful of interviews, wrote an autobiography, only made a few ABBA-related appearances and was so reclusive, she developed a reputation as being the new Greta Garbo.

But 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. "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 listening to 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 album's material covered familiar ground, Faltskog feared she was vocally "rusty" and actually consulted with a coach - twice.

"Who needs more?" Faltskog asked, with a laugh, adding: "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."

ABBA, which included Anni-Frid Lyngstad-Reuss, Benny Andersson and Bjorn Ulvaeus (Faltskog's ex-husband), has sold more than 300 million albums worldwide. The group is celebrated in ABBA The Museum, which opened last week in Stockholm.

While there aren't plans for ABBA to reunite, Faltskog said band members do 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."