Instead, the next big thing for Ulvaeus and Andersson following the "Kristina" concerts would be to write new material for a follow up to Mamma Mia!, he said, stressing it would not be a classical sequel, but a "looser kind of follow up."
While they had not yet decided on the format or the theme, Andersson said he had been positively surprised by the screen adaptation of Mamma Mia!, and had not ruled out another film or a continuation of the same theme.
Asked about sources of inspiration, Andersson just shook his head.
"Inspiration is overrated. It's all down to discipline. I have to keep working at it, and if I am lucky it will come. Then I have about one or two days of flow. Then it's uphill again," he smiled.
Luckily, the handsome black Yamaha grand piano standing in his studio can electronically remember what he has played and play it back to him.
Andersson said he listened to all kinds of music, mostly classical, and especially Johann Sebastian Bach, whose range and depth were "inexhaustible."
While Bach's cello suites were among Andersson's favorite pieces of music, he declined to mention any contemporary music he liked because he said he was not up to date with the current pop scene.
Instead, the music closest to his heart was Swedish folk music, he said, his face lighting up. Andersson received his first accordion when he was six years old – a classical instrument central to Swedish folk music that both his grandfather and father had played and taught each other.
"I think there is something very beautiful about being part of this folkloristic tradition. I feel grateful for being part – a small part – of something bigger," he said, referring to the act of keeping a cultural heritage alive.
For Andersson, Swedish folk music expressed and represented the Nordic climate of long, harsh, dark winters and short, light summers and the physical and emotional conditions people lived under as a consequence.
"I think there is an understanding in the music for our conditions up here. You can hear what kind of a life people have had up here in the deep dark forests – a hard life," he said pensively.
In fact, he speculated, perhaps it was the influences of Swedish folk music and its wide range of happy yet melancholic undertones that had made ABBA's music resonate in so many parts of the world.
"It's funny. I am always asked why I think ABBA has such broad appeal - from Galapagos to China and Egypt. Why does it work in all these different places? I don't know, but perhaps a part of it has to do with that melancholy below the gaiety."
Andersson's desire to feel part of a greater context might explain why he claims to feel friendlier towards the taxman than most multi-millionaires. He enjoys such rich men's hobbies as breeding racing horses and runs the trendy Hotel Rival in Stockholm, but insists he does not mind paying Sweden's high taxes.
"Yes I pay a lot of tax, but I like the idea of giving back to society," he said, adding there was quite enough money left after he had paid the hefty sums.
Another example of his social engagement was the elections to the European parliament in June when Andersson donated one million SEK to Swedish political party "Feministiskt initiativ" – the world's first feminist political party.