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)
