What is the tune that the band starts playing at about 2:19 in the linked video? I’ve only heard it in one other place other than the movie: I once heard it at a Caterpillar (tractor company) demonstration when my dad was working for the company.
If you have the movie they may tell you the song in the end credits. They usually list every song played,
It’s not listed on IMDB but it’s Sousa’s King Cotton March.