ABBA was a Swedish pop group formed in the 1970s that achieved great commercial success with catchy songs featuring harmonized vocals. Their music appealed to people of all ages and bridged generational divides. Hits like "Mamma Mia", "Dancing Queen", and "The Winner Takes It All" topped the charts and continue to be popular today. A film adaptation of "Mamma Mia" was also a box office success that featured the group's music to tell a story. ABBA went on to become one of the best-selling music groups of all time.