Songfacts®:

• The opening song for the 2016 musical film La La Land is a big ensemble production number set in LA traffic. It was shot in a six-minute single take on a 130-foot (40 m)-high freeway ramp in South Los Angeles.
• The upbeat and energetic number is the only fully ensemble song in the movie. The film's music director and soundtrack producer, Marius de Vries told The Independent:
  
  "It was a wonderfully deep process of collaboration with Mandy Moore and the choreography department, many weeks of planning and rehearsal brilliantly overseen by Music Supervisor Steven Gizicki, and a long and challenging journey with lyricists Benj Pasek and Justin Paul - because the piece acts as an overture to the story, it was really tricky to establish just exactly what the song should be about, but Benj and Justin eventually found the perfect balance between poetry and naturalism and between the specific and the general in this hymn to the daily LA routine."
• The song had a working title of "Traffic." Composer Justin Hurwitz told Genius:
  
  "In Damien's script, there were all the big moments, there was the big opening moment on the freeway which he described very elegantly in his script, you know… how music bubbles up from under the car radios and the girl in the first car starts humming along to it and then she gets out of her car and starts singing. And so our working title for that song, for a very long time, was just 'Traffic.' Even late in the process I remember… After Pasek and Paul wrote the words 'Another Day of Sun' and that title existed, all of the crew and department heads were still sometimes calling it 'Traffic.'"