We don't know, of course, but here's a guess based on the facts: He's French and has written some of the slickest pop songs of the decade; she blankets her movies in a musical ennui, careful to weave in a rare vintage gem; they're both fans of My Bloody Valentine, but you can't really dance to Loveless at a wedding. Sooo...
The Kinks - "Come Dancing"
Peter Sarstedt - "Where Do You Go to My Lovely"
Lykke Li - "I'm Good, I'm Gone"
The Jesus & Mary Chain - "Head On"
The Rolling Stones - "She's a Rainbow"
LCD Soundsystem - "Daft Punk Is Playing at My House"
France Gall - "Les Sucettes"
Nicki Minaj - "Super Bass"
Justice - "D.A.N.C.E."
Plastic Bertrand - "Ca Plane Pour Moi" (Sonic Youth's version also a high possibility)
M83 - "Graveyard Girl"
Siouxsie & the Banshees - "The Passenger" (Iggy Pop cover)
Goldfrapp - "Ooh La La"
The Concretes - "Can't Hurry Love"
The Strokes - "I'll Try Anything Once" (demo version)