How Nick Cave Wrote the Theme to ‘Train Dreams’ in His Sleep

The lyrics to Nick Cave and Bryce Dessner’s “Train Dreams,” the end-credits song in the movie of the same name, offer a chain of images that seem dark and confusing: a grizzly “big as a house,” a screaming locomotive, an elk with twisted antlers and “a boy called Elvis something / whose voice could drive young girls insane.”  

And yet Cave has fashioned those images into an elegant, haunting ballad that perfectly captures director Clint Bentley’s gentle but earthy fantasia and Joel Edgerton’s...