ABBA are a Swedish pop group formed in Stockholm in 1972 by Agnetha Fältskog, Björn Ulvaeus, Benny Andersson, and Anni-Frid Lyngstad. The group's name is an acronym of the first letters of their first names. They became one of the most commercially successful acts in the history of popular music, topping the charts worldwide from 1974 to 1983. In 1974 ABBA were Sweden's first winner of the Eurovision Song Contest, with the song "Waterloo", which in 2005 was chosen as the best song in the competition's history as part of the 50th anniversary celebration of the contest.
