Zooey Deschanel and Joseph Gordon-Levitt are actors that play music when they're not in front of the lens -- and, sometimes, when they ARE in front of the lens. Their cover of "What Are You Doing New Year's Eve?" is an example of the latter.

The "500 Days of Summer" co-stars have posted a darling video duet on YouTube of their live-performing the classic tune, with Deschanel on wee ukelele and Gordon-Levitt on a travel guitar. The She half of She & Him dons a tiara. Of course.

"When we did '500 Days of Summer'... we spent every lunch hour dancing to Marvin Gaye in the hair and make up trailer; we had loads of fun," Deschanel mugs on HelloGiggles.com (!!), the site she co-founded. Cute! "I hope to do a thousand more movies with him because he’s simply the best." Cuter!

Once you're done picking the sugar from your teeth, note that he's "Joe" Gordon-Levitt, and don't you forget it. Because it's the cutest. Cue gooey eyes, aw.

Should your twee quota of the year remain unfulfilled, check out "Scrubs" alumnae Zach Braff and Donald Faison sing "Baby, It's Cold Outside," a version which includes the phrase "It's a f*cking brush."

For more Deschanel, watch back episodes of "The New Girl" until it comes back on TV on Jan. 17 ("my birthday!" OH JUST STOP IT ALREADY). Gordon-Levitt will appear in "Dark Knight Rises" and is currently filming "Lincoln." He's also on tap for Quentin Tarantino's "Django Unchained."