(PEOPLE.com) -- Director Sofia Coppola and partner Thomas Mars, the frontman for the band Phoenix, are expecting their second child, the rocker has confirmed.
In a backstage interview with Chicago's WRIT, the French-born musician, seemingly surprised, nodded affirmatively when asked about partner Coppola being pregnant.
Coppola, 38, and Mars have been together for four years, and have a three-year-old daughter, Romy. Coppola was previously married to director Spike Jonze.
"I heard the story that if you play Bach, [babies in the womb] get smarter," Mars said.
Asked if he would play music from his band's latest album, "Wolfgang Amadeus Phoenix," Mars joked: "We have to study it. Not sure it's a good idea."
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