The ensemble number portrays drivers in a Los Angeles traffic jam on a highway ramp singing and dancing about their aspirations to succeed in Hollywood.
The song was filmed on location on a 130-foot-high express ramp of the Judge Harry Pregerson Interchange[1][2] in three shots, edited with hidden cuts to give the illusion of a single six-minute take.
[9] The sequence was initially planned to be on a ground-level ramp,[10] but it was changed to the interchange to give a sense of the vastness of the city.
[9] Director Damien Chazelle also likened the number's location on a highway to the Yellow Brick Road in The Wizard of Oz.
[12] Initial rehearsals with ten dancers occurred in a studio parking lot using about 20 staff members' cars.
Film editor Tom Cross noted that Chazelle "realized that for people to accept that it's a musical, you have to announce it confidently at the beginning," and then they realized that displaying the film's title on the final beat of the song was sufficient to make the song itself serve as a kind of overture to the musical.
It was performed by host Jimmy Fallon and featured cameos by Nicole Kidman, Amy Adams, John Travolta, Sarah Paulson, Rami Malek, Kit Harington, and others.