High Quality Content by WIKIPEDIA articles! Anni-Frid Princess Reuss of Plauen (born Anni-Frid Synni Lyngstad 15 November 1945 in Bjørkåsen, Ballangen, Norway), styled Her Serene Highness, is a Swedish singer (of Norwegian and German origin), best known as Frida Lyngstad, one of the four members of Swedish pop group ABBA.