Great thread, Jen Ellen. My father's father was a dispatcher and station manager on the Union Pacific his whole working life (except for a short stint on the SP) and his mother's brothers were engineers and dipatchers. Dad grew up mostly in converted boxcars and as a kid performed various chores around small town railroad stations in various western states and I've inherited his love of trains and locomotives in particular. In fact, you could make a good case for putting steam powered trains back into service as they were as fast as conventional diesels and could certainly be made to operate cleaner. Diesels, of course, would be more practical for yard work and similar tasks.
At any rate, some train songs:

Golden Rocket
Streamlined Cannonball
Rock Island Line
Bringing in the Georgia Mail (a Bill and Charlie Monroe tune which is my favorite)
Greenlight on the Southern ( a more recent classic by Norman Blake which has become a bluegrass standard)
and did anyone mention City of New Orleans?

vl