Songfacts®:

• This song was composed and orchestrated by Justin Hurwitz with lyrics by Benj Pasek and Justin Paul for the 2016 Damien Chazelle-directed musical film La La Land. The movie tells the story of aspiring artist Mia played by Emma Stone and jazz obsessive Sebastian, played by Ryan Gosling, who meet and fall in love in Los Angeles.
• Hurwitz recalled the story of the tune to Variety:
  
  "[The song] started at the piano with me just working on demos for Damien, sending him ideas until something really sparked. It's so funny that that and 'Audition' are the two songs that people seem to be responding to the most, at least so far, because they had similar processes in the sense that they had probably the least amount of fussing at the piano demo stage
  
  I was just composing it from an emotional place and thinking about the tone. I would say the tone is hopeful, but melancholy at the same time. And it kind of goes back-and-forth between cadencing in major and cadencing in minor, because I think that's kind of what the song is about. You have these great moments and then you have these less great moments in life and in Los Angeles and we see it happen in the story. I was thinking about that idea a little bit and just trying to compose a melody that I thought was shapely and beautiful. I guess it has some jazz inflections, because it's something Sebastian plays on the piano."
• The song appears three times in the movie, the first it is sung solo by Ryan Gosling's jazz traditionalist character before it becomes a duet with Emma Stone later in the film. Finally, the film wraps up with the tune being hummed by Stone. La La Land music director and soundtrack producer, Marius de Vries told The Independent:
  
  "This was the first lyric that Pasek and Paul gave us, and one of the earliest songs to start to feel fully formed. Because we had it up and running for a while, we took it through many permutations - duet, female lead, male lead… and it moved around quite a bit in the script before it settled down into its current position(s)."
• Ryan Gosling can't whistle, so that's Justin Hurwitz you hear whistling during this song.
• Emma Stone and Ryan Gosling performed their songs live on set, rather than lip-syncing to pre-recorded vocals.
• Ryan Gosling recorded his vocal for the song in an unusually low-key which was at his request. DeVries said: "For all of our studying of his voice, and preconceptions about where his voice should sit keywise, we were very much guided here in the end by his own instinct for Sebastian's character."
• This won an Oscar for Best Original Song at the 2017 ceremony, beating out songs written by Justin Timberlake ("Can't Stop The Feeling!" from Trolls), Sting ("The Empty Chair" from Jim: The James Foley Story), and Lin-Manuel Miranda ("How Far I'll Go" from Moana). John Legend performed it at the ceremony in a medley with the other La La Land song that was nominated, "Audition (The Fools Who Dream)." Justin Hurwitz also won for Best Score.