of Where Wood Grows
Wood is best for use if it is grown in a woods where there are no diseases and fires, but where the trees have to fight for space. This intense competition for sunlight and nutrients makes the wood dense, tight-grained, and beautifully resonant. But if the tree you choose has had to defend against fire, disease, or insect infestation, there may be hidden flaws or concentrations of unusual chemical imbalances in the wood. These can be visually beautiful and can even increase the strength of the wood, or enhance other qualities. But where music quality is concerned, these effects can only detract from the wood's quality.
Lastly, you want to get wood out of the center of a grove. Trees which grow at the edge of the woods, or solitary in an open field, are subject to twisting forces as the wind blows through their branches and foliage. Since no tree is symmetrical, the constant pressure of prevailing winds causes a characteristic "set," resulting in the grain of the tree spiraling up the trunk. Only at the center of a grove of trees does the wood grow straight up. When you cut a twisting trunk up for lumber, the grain is always running diagonally through the board, never straight along parallel to the direction of the board. This "grain runout" detracts from the acoustic qualities of the wood, as well as making the board weaker when it is sliced into thin pieces.
So forget about all those lovely yard trees your friends and neighbors offer you, sigh...