ABBA was a Swedish pop music group. The band consisted of Agnetha Fältskog, Benny Andersson, Björn Ulvaeus and Anni-Frid Lyngstad, who came together in the late 1960s, first performing as "Festfolket." Later topping the charts worldwide under the name of "ABBA," an acronym formed from the first letters of each of the group members' given names (Agnetha, Benny, Björn, Anni-Frid), their music ultimately gave birth to the immensly popular musical "Mamma Mia!" The stage version of that show opened at New York's Winter Garden Theatre, the venue Jolson opened, on October 18, 2001, and continues to run through the present.
On September 29, 1970, the four first appeared on television, billed as "Festfolket," singing "California, Here I Come." The arrangement was straight out of The Jolson Story, but the enthusiasm was all theirs!