Once upon a time, when I was an actor and my group travelled the civilized world, we spent a night in a small town in eastern Oregon.

Because we left our sleeping bags elsewhere, we had to sleep on the floor with blankets. It was uncomfortable and cold and not relaxing.

Later that night, two trains went through town, a mile or so away. They crossed very close to each other. I could hear their horns and the Doppler Effect mixed them together in a hauntingly beautiful cacophony.

It is one of the most lovely sounds I have ever heard.