Rock Songs starts as a walk of a few miles between the valley of the river Tywi/Towy and the heights of Y Mynydd Du/Black Mountain in Wales. It takes millions of years, meeting along the way the rocks and water that have formed the land, together with the trees, red kites and otters who pass through. Humans crowd in as well – saints, drovers, Romans, bikers and tourists. The great zen monk, Dōgen, is also walking and learns that mountains themselves walk, if you know how to look. Rock Songs began as a one-man movement performance of a river by Nick Sales and has become a book of...