Golden Globe winners Ryan Gosling and Emma Stone seem to be sailing straight towards Oscar nominations for their performances in La La Land. But, come Oscar Night, they might have to do more than sit and look pretty. With La La Land's "City of Stars" certain to get a nomination for Best Original Song, will Ryan Gosling and Emma Stone sing at the Oscars? Traditionally, the original performers of Oscar-nominated songs perform at the awards ceremony, with some exceptions, which means Stone and Gosling could be rehearsing more than just their gracious losing faces before the big night.
There are three different versions of "City of Stars" on the official La La Land soundtrack: one by Gosling, one with both Gosling and Stone, and a third that is essentially just humming. The most complete (i.e. longest) version is the one with both stars on the track, so I would assume that's the one they would perform at the Oscars. And, while Gosling and Stone both did their own singing in City of Stars, the fact is that they are not singers. Yes, Stone has performed in musicals on Broadway, and, yes, Gosling was on the Mickey Mouse Club, but it's hard to argue that singing is what they're known for.
I could see the "City of Stars" performance going one of two ways: either Gosling and Stone will perform in a highly choreographed production like the cast of Les Misérables in 2013, or John Legend will perform for them. It's likely it will depend entirely on Stone and Gosling's willingness to put their voices out there. It's one thing to do it in a recording booth, it's quite another to perform live in front of your peers and millions of viewers. Legend has a supporting role in La La Land and worked as an executive producer on the film. He's also a Grammy and Oscar-winning singer and songwriter with a voice of gold. If Stone and Gosling are too nervous or self-conscious to sing on the Oscar stage, then Legend would be a natural replacement.
Legend taking over singing duties for Stone and Gosling would not be unprecedented in the history of the Academy Awards. In 2005, Beyoncé performed nearly every nominee for Best Original Song, and she didn't even have anything to do with those films. My money is on Legend performing the song, but if Stone and Gosling do end up taking the stage to sing, then I fully expect to see Legend accompanying on the piano.