The Swedish singing group ABBA is one of the most successful pop groups of all time. Formed in 1972, the group consists of Benny Andersson, Björn Ulvaeus, Agnetha Fältskog, and Anni-Frid Lyngstad. They are best known for their hit songs such as 'Dancing Queen', 'Mamma Mia', and 'Take a Chance on Me'. ABBA has sold over 380 million records worldwide, making them one of the best-selling music artists of all time.