Something that distinguishes Abba fans around the world is their loyalty, says researcher Shanika Ranasinghe at the University of London, who has studied the culture among Abba fans since 2014.

- Many of the fans have thought that the group would come back with new music, and now they have been rewarded for their wait, she says to Kulturnyheterna.

Growing fan base

According to Shanika Ranasinghe, it is Abba's distinctive expression that makes fans hold on to the group almost as tightly as when they were still active - 40 years ago.

- Abba was something completely new and different when they broke through in Eurovision in 1974. Here in the UK no one had seen anything like it and we gave them and the song Waterloo zero points.

I think everyone was confused at first and wondered what was going on, she says.

In Shanika Ranasinghe's research, there is much to suggest that the fan base is still growing.

Younger generations have also been inspired by and fallen for Abba.

And the group has received some help along the way over the years:

- It is clear that the Mamma Mia! Musical and the films, other Abba films and lots of cover bands have also done their part to keep Abba fans, Shanika says.

"Swedish melancholy"

Abba is also considered to be more accessible and present with fans than other world artists such as The Beatles.

Many people have personal memories of being at a gig, getting an autograph or saying hello to someone in the group.

Despite the fact that many associate Abba with dancing and cheerful music, many of the fans that Shanika Ranasinghe spoke to highlighted the slightly darker strings in the group's music and lyrics.

- I have interviewed fans who believe that Abba has saved their lives, she says.

- Abba started as very glamorous and then it got darker towards the end.

This is what we call the "Swedish melancholy".

There is something very unique in the way Abba tells about universal things such as love, friendship, betrayal and grief, both through the music and the lyrics.