Mamma Mia! Here We Go Again: Everything you need to know about the ABBA cameos

Here they go again…

Björn Ulvaeus and Benny Andersson have been composing songs together since 1966, most famously for their beloved Swedish band ABBA, and the duo is still going strong as a team, making cameos in Mamma Mia! Here We Go Again.

Their fingerprints are all over Mamma Mia, having not only composed all the ABBA songs featured in the stage musical and films, but also as producers of the original musical and its two film iterations. As you might guess, the two were deeply involved with the soundtrack for Mamma Mia! Here We Go Again: Ulvaeus rewrote numerous lyrics to accommodate the plot, while Andersson oversaw the soundtrack recording.

For diehard ABBA fans, the two maestros also have a bit of onscreen fun in the film. Ulvaeus appears as a stuffy Oxford professor in the film's opening number, "When I Kissed the Teacher," while Andersson pops up as a piano player in a Paris cafe in "Waterloo."

Director Ol Parker says the experiences of filming those two cameos were vastly different because of the time involved. Describing the duo as "enormously generous and supportive" throughout the process, Parker admits that he thought Ulvaeus quickly grew bored during his two days shooting his number. "Bjorn was baffled by how long it all took and how boring it was," he recalls. "It's always tricky when someone who's not used to it volunteers to be an extra, and you want to go, 'Listen, you're going to be sitting there for a long time.' It's all right to be Benny in 'Waterloo' sitting at the piano because we're only pointing the camera that way briefly. But Bjorn was in for two whole days, sitting there reacting to Lily [James], which I don't think he quite budgeted on."

Still, Parker was ultimately thrilled with the results, which included a sequence of Ulvaeus dancing with a feather boa onstage that ended up in the outtakes. "He was great," Parker says. "He loved it. There was something a little worrying to me about having a celebrity cameo within about three minutes of the film starting. That seemed a little smug. But it just seemed the right place for him, and he was very funny."

Andersson's cameo was a bit more in line with his career as a songwriter, placing him behind the piano. For actor Hugh Skinner, who sings lead on "Waterloo" as young Harry (portrayed by Colin Firth in the present day), Andersson's cameo was both fun and nerve-racking.

"If that was the first time I'd met him, I probably would have keeled over, but we met him in the studio recording the songs when he was mixing, which was an extraordinary thing, singing ABBA to ABBA" says Skinner. "He's obviously a complete genius and a phenomenal songwriter. He's written all these timeless songs, but on top of that, annoyingly, he's also incredibly lovely and nice and generous, which makes it more scary because you don't want to disappoint him."

Cinematographer Robert D. Yeoman says Andersson had as much, if not more fun in between takes. "We were getting ready to shoot and he was sitting at the piano," Yeoman recalls. "He's a mischievous guy, and he started playing 'Rule Britannia' because the crew was all English. Everyone gathered around the piano and they all started singing. Everyone is laughing and having a great time. It was one of the things that happens on the film set that makes it all worth it."

Yeoman says that was one of his favorite moments from a set that was bustling with warmth and energy. "Benny was spoofing the Brits a little bit," he says. "It was fun, and it was all done in a warm spirit. It was one of those things that happen on a set, totally out of the blue, and it's just like, 'Wow, that was really magical.'"