Ghost riders, veiled specters, love, God, murder and all that—the Man in Black can sure spook a gal. But sometimes Johnny Cash is scary in a whole different way. He was such a badass for so long that the most frightening thing he could ever do was to make himself look silly by accident. Feeling embarrassed for Johnny Cash is completely intolerable. It's not that his dignity is fragile, but it's so important, so elemental, that the mere possibility of it being threatened is terrifying. It's like the first time you find out the great and powerful Oz is just a trembly little old man. It's happened, too: Check out some of those old song arrangements, the hairstyles, the odd TV special. It's no fun admitting, but it's true, he's had some downright cheesy moments. He walked the line, and once in a while he crossed it.

Luckily, there's no such danger here. Billed as "a nostalgic look at the history of the American railroad as told in story and song by the legendary Johnny Cash," Nicholas Webster and Dyann Rivkin's documentary was originally filmed and aired in 1974. Just shy of an hour long, it uses a variety of narrative devices, including elaborately staged re-creations of historic events and defining moments in train history. We see the first-ever trainjacking, in which Northern soldiers posing as Southerners stole a train from Big Shanty, Ga., and tried to flee up north with it. Victorian paper-doll diagrams describe early experimental trains, including some powered by sails and horses. A rogue's gallery of characters appears along the way, from train robbers, hobos, cowboys and workmen to robber barons and railway financiers.

It's not a completely smooth ride. A segment on steel-drivin' man John Henry plays like a karaoke video. And the ending feels a bit like an Amtrak commercial. But it's worth enduring any rough spots just to see Johnny Cash, dressed in ever-rotating tuxedos, singing train songs while hanging off antique steam engines, riding in boxcars and sitting around a campfire. It's like having the Man in Black personally guide you through a railway museum. And that's pretty cool.