The prospect of singing and dancing on screen in Mamma Mia! was ‘seriously scary” for Stellan Skarsgard.

But when the call first came asking if he would join a cast headed by Meryl Streep, he just had to accept.

“I didn’t hesitate at all,” he recalls.

“My agent called me and said ‘Stellan can you sing?’ and I said ‘no’ and then he said ‘because they are making a movie out of Mamma Mia! with Meryl Streep.’ I said ‘I can sing!’

“I would probably have said yes even if she wasn’t in it but you know Meryl wouldn’t do a thing like this unless she had a very good idea about how to do it.

“It’s guaranteed that with someone like Meryl in it something interesting will happen. And also you want to work with good actors – and she is a very good actor.”

The Swedish-born star is also one of the most respected actors in the world but performing in a musical – based around the songs of his compatriots, ABBA, one of the most successful pop groups of all time – wasn’t exactly on his list of priorities.

“No, it wasn’t so it was a surprise to be asked. But what I liked about it is that I was doing something that I’d never done before and I was really scared.

“I try to become a better actor all the time and it did help me. Not because I will become a great singer and dancer – I doubt that! I tried to lose control a lot when I did this film.

“My kind of acting is usually quite measured – even if it is alive, even if I do react to what is happening on the set, it has a certain control to it. In this film I just threw everything away.

“I stopped thinking about acting and just had fun and I wanted to see what happened. It was great fun.”

Mamma Mia! is the joyous, poignant story of a young woman, Sophie (Amanda Seyfried), who discovers her mother’s old diary just before she is about to marry the man she loves, Sky (Dominic Cooper) on the idyllic Greek island where she lives with her mother, Donna (Streep).

Sophie has always wanted to know the identity of her father and from the diary discovers that there are three of her mother’s former lovers who could be her Dad – Sam (Brosnan), Harry Bright (Firth) and Bill (Skarsgard) and so, without telling her mother, she decides to invite all three to the ceremony with hilarious and often riotous results.

For the three men, it’s a reunion with a beautiful woman who they loved and lost, many years before. For Donna, it’s a headlong collision with her past and her wild youth.

Anderson is a free spirited adventurer who sails the world seeking new thrills.

“He’s a bit of a bimbo,” laughs Skarsgard. “This was written by a woman, directed by a woman, produced by a woman, the three main characters are women.

“It’s the absolute reversal of a normal film which means the men in this film are portrayed like women normally are – that’s why they are bimbos. I don’t mind that.

“It’s very relaxing to be the bimbo – you have no responsibility whatsoever you just have to walk around show your buttocks and be cute!”

Skarsgard, 57, was born in Gothenburg and was already a successful actor in his homeland when ABBA exploded on to the pop scene in the 1970s and at the time, he wouldn’t admit to himself, that he actually liked their music.

“When ABBA were at the height of their popularity I was trying to be cool so I had to listen to more indie pop and experimental jazz and stuff so it took me quite a few years before I was brave enough to admit that I like listening to ABBA.”

Now, he says, ABBA are rightly regarded as a national treasure in Sweden. “They are part of our heritage. Everybody knows of them and knows their songs and they are frequently played on the radio.”

Skarsgard now lives in Stockholm but is in huge demand all over the world.

His CV includes Breaking The Waves, Amistad, Deep Blue Sea, Dancer In The Dark, Helen of Tory, King Arthur, Goya’s Ghosts, and Pirates of the Caribbean: At World’s End.

Q: Is it one of the nice things about Sweden, that people don’t bother celebrities like that?

A: Yes, and it’s very pleasant to live there in that sense. I get more people come up to me on the streets of New York than I do in Stockholm. The Swedes see you and maybe recognise you but then they look away (laughs).

Q: What was the appeal of this for you? Did you think it would be like an adventure with some singing?

A: The adventurer is a little closer to me than the singer to me actually. (Laughs).

Q: Your character is a bit of an old hippie. Did you used to be a hippie?

A: At that time I was already an actor, I started early, and so I had to be in the theatre every evening so I could only be a hippie on Mondays. So I was a Monday hippie.

Q: Did you have singing lessons?

A: Oh yeah, I’ve worked hard on the singing and it might have helped a little bit, too. But they can fix it, you know. They can change everything.

Q: So what was it like when you saw yourself on the screen in Mamma Mia?

A: I’m very proud. But I think I’m the worst singer in the film. I think part of the charm of the film is that we are not professional singers. It’s not glossy, it’s not elegant, and it has a lot of flaws, which makes it very human.

Q: Can you explain the enduring quality of ABBA’s music?

A: I don’t know, they catch on and they stick in your head and musicians – who understand these things better than I do – tell me that they are actually quite intricate and complicated and intelligently written.

Q: What was it like on the set when you had to film your song?

A: We pre-recorded all the songs so that we could have them on play back when we shot the scenes. And that was frightening.

I went to a studio in London to record the songs. But I got to the studio and found that there were two normal Swedes there – Benny and Bjorn – and then it became a lot easier because Swedes are very egalitarian and everything was relaxed and calm and they obviously knew what they were doing and they weren’t worried at all, so that was nice.

Then Pierce (Brosnan) and Colin (Firth) came and that was the first time I’d met those guys and all three of us were staring at each other and we were all a little shy and we didn’t know what was going to happen with this strange project we were involved in.

A couple of minutes later we were standing in the studio singing together about walking hand in hand in Paris and looking each other in a very strange way! (laughs).

Q: Do you think that each actor brings something unique to a project that can inspire you?

A: Yes. Mainly the thing is that it’s a collective work and the scene is never better than the weakest link in it and if you work with good actors you become better yourself. I don’t like doing solos or monologues, I like working with actors.

Because when you do a scene what happens on the set is always more fantastic than you ever could have imagined at home sat at your desk because you build on each other’s ideas while acting. It’s great fun and that’s why I still do it.

Q: And a good director works with that kind of collaboration?

A: Of course. Some actors and directors think that filmmaking is realising the ideas they had at home and that always takes out the life from what you do.

To create life from those two dimensional images it has to have all the irrationality of life and all the pitfalls and the strange rhythms that you cannot plan and they only exist if the actors and director are working together on the set and not only realising what they thought up before.

Q: Does every role end up being a little different than you expected it to be when you first accepted it?

A: Yes, it does. What I do when I prepare a normal role – and this is not a normal role, this is a bimbo – but when I do is I first think about what is necessary for the film. What does this role have to do to make the film work?

Q: What did this role have to do for Mamma Mia?

A: In this one I only had to sing and dance and be happy and look cute! (laughs) But you have latitude too – how does he move? What is he afraid of? What does he think about things? Then you carry this to the set. Then what the others do and what the other actors bring to it, which can make you go in a certain direction.

Some of it is pure chance but you know within which framework you have to work. There’s not one right way to play a scene or make it work, there are a million right ways and there are a million wrong ways.

Q: The director, Phyllida Lloyd, hasn’t had a lot of experience with film before this. How was it working with her?

A: She is a very accomplished theatre director and she knows actors and she knows an audience and she knows Mamma Mia! She knows exactly what she wants from it.

When you came up with suggestions she would say ‘no, that’s not a Mamma Mia! thing’ or she would say ‘yes, that’s a Mamma Mia! thing.’

Because she knows the tone and she’s already tried it all over the world. That was very comforting because she knew exactly what she wanted and what she needed. She delegated a lot, she had a talented cinematographer and costume people, they were all talented. But she still made the decisions according to her taste, so she was in control.

She was calm throughout and very thoughtful about everything and she also has a great sense of humour.

Q: Was it flattering to be cast in this role? Your character is a bit of a hunk.

A: (laughs). Yes, it was. But this was written by a woman, directed by a woman, produced by a woman, the three main characters are women. It’s the absolute reversal of a normal film, which means the men in this film are portrayed like women normally are – that’s why they are bimbos (laughs). I don’t mind that.

It’s very relaxing to be the bimbo – you have no responsibility whatsoever you just have to walk around show your buttocks and be cute! (laughs). It’s fun. They are extremely strong, those women and it’s good. But I’m from Sweden and we’re used to strong women, we’re very emancipated there.

I don’t understand men who are afraid of emancipated women because life is much easier when you have equality. Because women can take care of themselves and if you have to go to a bar you don’t necessarily dance for three hours and then court for three weeks because the woman at the bar says ‘come on, let’s go home and make love.’ (laughs)

Q: You’re from the north of Europe but your job takes you all over the world. Is that something you enjoy?

A: Well, I feel comfortable on a movie set because that is a world I know and wherever that is, everything else revolves around it. I don’t travel when I’m not working because I travel so much when I work but I really like to travel when I work. Since you work with local people you get into the society immediately and you don’t end up where all the tourists are, which is nice.

Q: What was it like to dress up in all the ABBA gear – the platform boots and the latex – at the end of the movie?

A: I became an actor because I wanted to be dressed like somebody else or be somebody else. But that costume was the most extreme thing I’ve ever worn. But I knew also that my children would laugh their heads off. When we were looking at each other in those costumes we were absolutely convinced that none of us would ever work again (laughs).

Q: Are you a fan of musicals?

A: No, not really. There are some good musicals of course, but I’m not a person that goes to musicals.

Q: You work a lot in English. Is that easy for you?

A: I’m fortunate to be able to work all over the world but I haven’t done much in Sweden in the last decade. I work mostly in English and it’s not my first language so it means you have to work harder. Even if you are good at it, you have to work harder because it’s your second language and it’s not that close to you. I would say I work three times as hard when I speak English than I speak Swedish.

Mamma Mia! will be released on DVD on Monday.