There are other videos out there worth watching. Gandy comes from the company that made the tools. The dancing part is obvious. :)
A couple of things I found interesting in the first video. Note the shape of the hammers used to drive the spikes. The head is much longer than a normal sledge hammer. Made that way to clear the rail if the spike is on the other side.
Also look at the expressions on the faces as they watch the machine drive spikes. They are watching automation replace them.
This one from 1929 is interesting also.
My best friend's grandfather was a section foreman on the Apalachicola Northern Railroad in the Florida Panhandle. His grandmother was a station agent in Greensboro, Fl. That was in the 1930's and 40's.