Over the years i have often wondered why Sweden seems to have good luck with their pop music outside of Sweden? Maybe because we have a long tradition of making easy listening pop? I doubt there will be any clear answers. Many of the influences took place long before i was born so im sorry if im mixing up things since its second hand information. I know that my parents danced to all of the below mentioned bands back in the day :) This is a taste of the Swedish music history a la Youtube.
Since a long time back people have always had an interest in folk music, but it wasn't until the pop music came here that it had a big impact on people in general. It feels likely that when The Beatles had a live performance on TV in Sweden just before their breakthrough they opened up to followers like Tages, Shanes and Hep Stars. All of them big stars in Sweden during the 60ties and 70ties. Sven from Hep Stars later became the second part of Svenne & Lotta in the 70ties and they made music together with Björn & Benny from Abba. Of course there is no denying the greatness of Abba and their great pop music that spread over the world after the Eurovision Song Contest 1974. Their music is still very popular, but i must say that i prefer the original over any spinoff-movie-musical any day.
It makes sense that our generation keeps on making great music, because the influences from what out parents listened to keeps on inspiring new talents today.
The Beatles (Swedish Television 1963)
The Hep Stars
Svenne & Lotta
Abba (Eurovision contest 1974)
Of course this is just a small part of what people listened to in Sweden back in the day. Take the chance to discover more via similar artists on last.fm.
If you want to read more about Swedish pop history read this article on DN with Google translator.