It's Apple's first original contribution to a movie, which makes the singer eligible for an Academy Award nod. It's not her first time dabbling in film though: She covered the Beatles' "Across the Universe" for Pleasantville in 1998, and her song "Paper Bag" was featured in Bridesmaids.
Apple collaborator Jon Brion put together the soundtrack for This Is 40; he also produced her albums When The Pawn . . . and Extraordinary Machine. While Apple's track has yet to be released, you can check out snippets of Brion's score at the Universal Pictures' Academy Awards consideration site.
This Is 40 is a spin-off of Apatow's Knocked Up, focusing on the family life of Paul Rudd and Leslie Mann's characters Pete and Debbie. The film hits theaters on December 21st.