Out of the choked Devonian waters emerged sight and sound and the music that rolls invisible through the composer's brain. They are there still in the ooze along the tideline, though no one notices. The world is fixed, we say: fish in the sea, birds in the air. But in the mangrove swamps by the Niger, fish climb trees and ogle uneasy naturalists who try unsuccessfully to chase them back to the water. There are things still coming ashore.