Hi Ralph,
Aside from the structural changes induced by exposure to a degree of heat and cold and in the composition of the glues used, the areas of maximim vibration on the top-plate, called nodes, flex in a predictable pattern which in most cases expands with age, and ""sets""as a memory in the wood itself. These are called Chaladni Patterns.
These nodes are distinct from the nodes you would use to check intonation, or for harmonics.
An even more interesting question would be: Do guitatists get better with age?
