Who sang background on the song En karusell when they were just 27 years old?
En karusell:  Future members of ABBA Agnetha Fältskog and Anni-Frid Lyngstad did backing vocals on the song but were not credited for their contribution.The B-side song on the Swedish release was titled "Att finnas till" and the B-side song on the Japanese release was titled "Lycka".
i don't know