Following the immense success of both Mamma Mia! on stage and Mamma Mia! The Movie, Björn was looking for his next pet project.

In his own words: "They seem to make people happy, they kind of get you in a party mood and everyone loves a party. The idea for another experiment gradually grew — maybe you could have a party in a sort of Mamma Mia! environment! Yes, but what exactly would that environment be? Well, the obvious place for such a party would be in a taverna on the island of Skopelos, where most exteriors of the movie were shot. This imagined and wonderfully exotic Greek taverna and its equally exotic landlord, Nikos, have been magically transferred to Sweden and when you step through the doors for the first time you’ll feel as if you’re right in the heart of a Greek island paradise! You’ll be eating great Mediterranean food, drinking, singing, dancing and “having the time of your lives” (sorry about that) in a Mamma Mia! world. Whatever the weather outside, it’s always a beautiful, warm summer evening inside the Nikos Taverna. Oh, and did I mention that all your favourite ABBA songs are part of the experience?!"

Mamma Mia! The Party had its première on Wednesday 20 January 2016 and was attended by all four ABBA members.  

They each arrived separately: Björn arrived first with wife Lena; Frida followed with her man Henry Smith; Benny arrived with wife Mona and Agnetha arrived with Thomas Johansson. They all posed for photos on the blue carpet and Björn, Benny and Agnetha did most of the talking to the press.  In fact, I have yet to see even a snippet of Frida actually stopping to talk to the press.

At the end of the evening, all four of them got on stage together - for less than a minute - and waved to the crowd and took huge applause.  Apparently Frida and Agnetha had been seated together and had had the idea together and then approached Benny and Björn with it who obviously did not object.  Björn probably felt it would be great promotion for Mamma Mia! The Party!

There was no official TV footage of this magical moment but several people managed to film it and photograph it from all angles.  

 

Various news footage, mostly in Swedish: 

1. SVT
   Broadcast: Sweden
   Footage of all four ABBA members on the blue carpet - and brief chats with both Björn and Agnetha (separately).
   
    
2. Nyhetsmorgan
   Broadcast: Thursday 21 January 2016, Sweden
   Their report started with footage of ABBA together on stage and then of the arrivals and included brief interviews with Marie Ledin (with Tomas Ledin in the background), Tommy Körberg and Helen Sjöholm (with Peter Grönvall in the background).
   
    
3. Expressen
   The Swedish newspaper had two reporters on the blue carpet and so managed to get two interviews with Benny and Björn and a few words with Agnetha. 
   
    
4. AFP
   Raw interview footage and short comments from each of Benny, Björn and Agnetha in English.
   
    
5. Australian report (Don't know where from)
   A quick interview with Björn (footage gets cut off however)
   
    
6. Aftonbladet
   Footage of each of them arriving
   
    
7. The Telegraph
   A short interview with Björn

Naturally, the appearance of all four of them together made worldwide news:

News Aritcles:
ABC, Australia
The Age, Australia
The Guardian, UK
Daily Mail, UK
The Telegraph, UK
Ekstra Bladet, Denmark
BT, Denmark
Irish Times, Ireland

Thanks to Luke Rogers, Kaarin Goodburn, Diirk Bracaval, Johhny Rathlau, Gunnar Moe, Jack McCarthy, LC, Terese Wedelin, Monique Hoevens and Ángel Herrera c/o ABBAtalk
Thanks to Pascale Ranson c/o ABBA Village
YouTube links c/o 

Paps Channel Sweden, Agnetha Fältskog admirer, Nyhetsmorgon, ABBAtalk, laurka3211, Your Disco80 Needs You, Expressen TV, Jessica Bell, News First
Thanks to all attendees at the première who took and shared their private footage.