(L-R) Swedish singers Benny Andersson, Anni-Frid Lyngstad, Agnetha Fältskog and Björn Ulvaeus, of the Swedish supergroup ABBA, pose for a portrait at Polar Studios in Stockholm, Sweden, May 1981. (Photo by Oscar Abolafia/TPLP/Getty Images)
Swedish pop group Abba, wearing kimonos, 1976. Left to right: Bjorn Ulvaeus, Agnetha Faltskog, Frida Lyngstad and Benny Andersson. (Photo by RB/Redferns/Getty Images)
(L-R) Technician Michael Tretow sits behind the audio mixer sound board with Swedish musicians Björn Ulvaeus and Benny Andersson, of the supergroup ABBA, at their Polar Studios in Stockholm, Sweden, circa 1977. (Photo by Oscar Abolafia/TPLP/Getty Images)
