Göran Bror Benny Andersson Born In Stockholm Sweden On 16 December 1946 Is A Swedish Musician Composer A Former Member Of The Swedish Musical Group ABBA 1972-1982 And Co-Composer Of The Musicals Chess Kristina Från Duvemåla And Mamma Mia!. Currently Active With His Own Band Benny Anderssons Orkester BAO! And Executive-Producing The Film Version Of The Musical Mamma Mia!.