The 101 Number one song of the day was written for a specific scene in a movie but it wasn’t at all what the producer had requested. The writers refused to change the song so the producer changed the movie.
The movie producer wanted the song to last eight minutes to fit the scene he had in mind. He also wanted a nice dance tempo, then a romantic interlude, then “all hell would break loose at the end.” He also wanted the same phrase repeated over and over. The songwriters ignored the instructions and came up with something entirely different and refused to use the requested phrase because they thought it was 1) “corny” and 2) other songs had the same or similar title. The songwriters prevailed and went onto record their song the way they wanted it and even so it was used in the movie trailer. And that was enough to launch it to number one where it landed on February 4th, 1978. And the phrase they refused to use over and over was – Saturday Night, Saturday Night. Instead the BeeGees came up with “Stayin’ Alive” (Saturday Night Fever did fine anyway)