What the young man laments is that he hasn’t learned the interconnectedness of the individual inhabitants of the rain forest—their ecology, interdependence—how the forest acts and lives as a whole. A “song” can be both an internal message—a hum—and, equally, an external one: a message sent out from one being to another to signal interconnectedness and cooperativity (songs are often sung together, or to one another). We can name cells, and even systems of cells, but we are yet to learn the songs of cell biology.
