The history of musical instruments is nearly as old as civilization itself. The role of acoustical science in this context is quite recent, but far-reaching; it aims to understand the physical basis for all the details of the production of sounds by musical instruments. However, over the centuries musical instrument makers and musicians have developed skills, traditions and an understanding of their arts, and they are often aware of subtleties in musical sounds that remain undetected by modern acoustical instrumentation. It is only within the past few decades that musical acoustics have achieved even a reasonable understanding of the basic mechanisms determining the tonal quality of many instruments. In some cases even major features of the sounding mechanism have only recently been unravelled. This book describes the results of such acoustical investigations. It is hoped that, through these investigations, researchers will ultimately give physical criteria to distinguish a fine instrument from a mediocre one. At that point, science may be able to come to the help of music in moving the design and performance of contemporary musical instruments closer to the ideal. Addressed to readers with a reasonable grasp of physics who are not put off by a little mathematics, the text discusses most of the traditional instruments currently in use in Western music.