ABBA is a legendary pop group from Sweden that was formed in 1972. The group consists of members Agnetha Fältskog, Björn Ulvaeus, Benny Andersson and Anni-Frid Lyngstad. ABBA are known for their melodic songs and harmonious vocals, and they achieved international success during the 1970s and 1980s with hits such as "Dancing Queen" and "Mamma Mia".