He speaks to Skansen guide Nelly Ekström, an expert on Julius Kronberg, the man whose art studio was chosen as the perfect backdrop for the cover shot.
We also hear from other fans of the group, explaining what it is about Abba that got them hooked.
Abba expert Carl Magnus Palm was also on hand to explain what the fans have meant for Abba themselves, in some part bringing them back into the public eye in the early nineties, when a range of famous fans started paying their tributes to one of the best-selling bands in music history.
The music in the programme was voted on by visitors to www.radiosweden.org The top ten songs were:
- The Winner Takes It All
- The Day Before You Came
- Dancing Queen
- Knowing Me, Knowing You
- The Visitors
- I Let The Music Speak
- Lay Your Love On Me