ABBA's Benny and Bjorn Rate Meryl Streep's Singing!

Meryl Streep may be primed to deliver pitch-perfect renditions of beloved ABBA hits in 'Mamma Mia!,' but how does her singing sound to the ears of the supergroup's founding fathers, Benny Andersson and Bjorn Ulvaeus? ET's Jann Carl caught up with the legendary rockers for their impressions!

In the film, Meryl plays an independent single mother who boasts a formidable set of pipes. "You need to be able to sing," Benny says of the part. "Fact is, she's incredibly good."

"She will astound the world, I think!" adds Bjorn.

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