Benny Andersson

Göran Bror Benny Andersson (born 16 December 1946), known professionally as Benny Andersson, is a Swedish musician, composer, former member of the Swedish musical group ABBA (1972–1982), and co-composer of the musicals Chess, Kristina från Duvemåla, and Mamma Mia!. As of 2011 he is active with his own band Benny Anderssons Orkester (BAO!), and was executive producer for the film version of the musical Mamma Mia!.

source: Wikipedia