Born: December 16, 1946. Göran Bror Benny Andersson is a Swedish musician, composer, producer, member of the Swedish music group ABBA, and co-composer of the musicals Chess, Kristina från Duvemåla, and Mamma Mia!. For the 2008 film version of Mamma Mia! and its 2018 sequel, Mamma Mia! Here We Go Again, he worked also as an executive producer.