Susan Stamberg: “The scene was filmed with 30 professional dancers and more than 100 extras on a 104-degree day. They first rehearsed in a parking lot, and later the actual freeway at 3:00 o’clock in the morning. On paper, Moore and director Damien Chazelle mapped out where the cameras would go. That morphed into 3D on a model ramp with toy cars. Then it was show time, which meant shutting down the freeway ramp for two days of shooting. All in all, it took 47 takes — for a three-minute and 48-second dance number that occurs entirely before the movie title looms up on screen.”