Sofia Coppola, Thomas Mars

Sofia Coppola and her longtime boyfriend, Thomas Mars of the band Phoenix, are expecting their second child, he confirmed.

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"I heard the story that if you play Bach, [babies in the womb] get smarter," Mars told Chicago's WXRT, adding that he probably won't play tunes from Phoenix's new album, Wolfgang Amadeus Phoenix, for the baby. "We have to study it."

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Coppola, 38, and Mars, who have been together for four years, are already parents to daughter Romy, 3. The Oscar-winning screenwriter and director's next film, Somewhere, will be released next year.