They were GREAT.
The brunette in ABBA was actually Norwegian.
Interesting life story. Her mother was 19 and had a fling with a Nazi soldier in occupied Norway. She had his child after he was shipped back to der Fatherland.
A couple years later she died of a kidney ailment.
Nazi collaborators and their bastard children were not treated very kindly in post-war Norway, so her grandmother took her to Sweden to raise her in peace. Years later the German equivalent of People Magazine located her father and ran this story back in the 70’s. She did meet and form some relationship with him until he died about a decade ago.
Then there was "Ace of Base"