3/4 time in music: think of a waltz. 1-2-3, 1-2-3…
Nancy's part was waltz time, if you will and when it switched to Lee it was 4/4 or "standard" like most popular music.
It was what MADE the song.
Chucking that away- It would be like making a Muppet movie, but saying "first, let's loose the puppets!"