The song comes only on the way back.

Geibikei is two kilometers of limestone in southern Iwate, cut by a small river called the Satetsu. The walls are pale, nearly white, and around the middle of October the color starts at the top of them and works downward. When it reaches the water, the gorge is at its fullest.

You go up before you come down. One boatman, one wooden pole set against the rock — the current is slow enough that this works. Half an hour to the far end, then twenty minutes on foot to a great rock face where people throw small clay balls at a hole in it, for luck. Then the boat turns, and there is nothing left to do but drift.

That is when he sings. The song is called Geibi Oiwake, and it did not begin here: a man from this valley traveled to Hokkaido in the Meiji years, studied under a master of the Esashi Oiwake, and carried the form home. A song from the northern coast, now sounding off limestone walls far from any sea.

Look at the bow before you board. It is flat and broad rather than pointed, because these boats descend from ferries that carried horses across the river, in a province that lived by horses. They are still built by hand, from cedar, over roughly a month.

You cross the same water twice. Going up, you watch. Coming down, you listen.