ABBA

ABBA ( AB-ə [ˈâbːa]) were a Swedish pop group formed in Stockholm in 1972 by Agnetha Fältskog, Björn Ulvaeus, Benny Andersson, and Anni-Frid Lyngstad. They are among the most renowned and commercially successful musical groups in history. In 1974, ABBA won the Eurovision Song Contest for Sweden with their song "Waterloo". In 2005, "Waterloo" was chosen as the best song in the competition's history during its 50th anniversary celebration. During their peak, ABBA comprised two married couples: ... source: https://en.wikipedia.org/wiki/ABBA