ABBA reunion: Benny Andersson says band has 'nothing to prove' with new songs

But Andersson, 71, said: “I don’t feel that we have to prove anything.

“I don’t feel we have to think about, ‘Oh, what if it was better before?’

“Maybe it was, but we can’t care about that. We do it because we think it was a good thing to do.”

And he added: “We enjoyed it very much. We’ll see. I hope you’ll like them.”

The star said the songs came about while he and fellow original bandmember Bjorn Ulvaeus, 73, were in the studio working on a project where the band will tour as avatars .

“So we said, ‘Hmm, maybe we should try and write a couple of songs, ask the ladies if they want to come in and sing’. And they said, ‘Yeah, absolutely’. So it was just, out of pure joy I’d say.”

He also revealed further details about the sound of the two new tracks – but added that they had not yet been completed.

“One of the songs is like we would’ve written it [for] today. The other, we could’ve written in 1972. So I don’t know, we’ll see. I mean, they’re not finished yet,” he said.

“We have the vocals, they’re all recorded, we haven’t mixed it, we haven’t worked them through, really, but I think they’re pretty good.”

Asked whether he thought it would complement Abba’s legacy, Ulvaeus, said: “I think so. It certainly sounds Abba very much.”

Andersson added: “As soon as Frida [Anni-Frid Lyngstad] and Agnetha [Faltskog] start singing, that’s when it sounds Abba.”

The pair were speaking at the press night for Chess, the stage show they wrote with lyricist Sir Tim Rice.

The musical has just returned to London’s West End.

The production, from English National Opera, stars Michael Ball and Alexandra Burke.

The show tells the story of rival chess players competing for Russia and the USA during the Cold War.

Stars turned out in force for the first night, with guests including actors Joe McFadden, Luke Evans, Mark Gatiss and Tom Conti, comedian Rory Bremner and singer Chesney Hawkes.

Elaine Paige, who was in the original West End cast, also attended on Tuesday.

The revival received a standing ovation from the audience, as Andersson, Ulvaeus and Tim Rice joined the cast at the curtain call.

Speaking after the performance Michael Ball described the show as a “spectacle” and said it has an “epic score”.

Last week, Abba fans welcomed the announcement that the band have reformed and recorded new material.

The two male bandmembers said it was “wonderful” to be back in the studio with their former bandmates, adding it was like “no time has passed”.

Asked about the secret of their success, Ulvaeus said: “We’re still curious, both of us. Trying new things is still exciting.”

Andersson quipped: “Recording an Abba song is not really new but it felt good anyway.”