Agnetha Fältskog, Björn Ulvaeus, Benny Andersson, and Anni-Frid Lyngstad are all members of the 70s pop group ABBA. The quartet formed in Stockholm, Sweden in 1972 and quickly rose to international fame with hits such as "Dancing Queen," "Mamma Mia," and "Waterloo." Known for their catchy melodies, elaborate costumes, and genre-defining music videos, ABBA remains one of the most successful pop groups of all time. The group disbanded in 1982 but continues to influence and inspire artists today.