Sound from acoustic guitars may soon become more melodious for environmentalists. Hiroyuki Yano, Yuuzoh Furuta and Hiroyuki Nakagawa of the Kyoto Prefectural University in Japan have discovered a replacement for Brazilian rosewood, an endangered tree that has been used to make the backs and sides of the best guitars. The researchers started with a tree that can be grown in sustainable plantations, the Japanese cedar, and tried to give it the acoustic properties that make rosewood such a desirable material. The density of cedar is less than one-third the density of rosewood, and is far less stiff. So the researchers compressed strips of cedar at 150