Producer Judy Craymer pitched the idea of “Mamma Mia” as a stage musical in 1982 to Bjorn Ulvaeus in a car ride from the airport, later pitching it to Benny Andersson as well (both members of ABBA) (Reinhardt 2021). In the first “Mamma Mia” movie, Andersson played the piano on the dock while the cast performed “Dancing Queen” (Reinhardt 2021). Ulvaeus appeared in the ending credits as a Greek god during the cast’s performance of “Waterloo” (Reinhardt 2021). Benny Andersson would also go on to compose the original score for the film as well (ABBA: The Official Site n.d., “In Focus: Mamma Mia! – The Movie”). ABBA’s official last performance as a group was in 1986, with Andersson and Ulvaeus being the band members with the biggest input on the musical and the film.
“It was self-evident that Benny Andersson – the man who, in partnership with Björn Ulvaeus, wrote and produced all of ABBA’s recordings way back when – would be in charge of the soundtrack recording. To get that authentic sound, a selection of the original musicians ABBA used on their recordings were asked to take part in the Mamma Mia! recordings: at the core during the sessions were bassist Rutger Gunnarsson, guitarist Lasse Wellander and drummer Per Lindvall, with Benny himself on keyboards.” (ABBA: The Official Site n.d., “In Focus: Mamma Mia! – The Movie”).