This paper is divided in two parts: first part corresponds to a review of newest sound synthesis techniques, while the second part contains the development of an automatic tuning system based on a fuzzy logic controller intended to emulate the human expertise in this field. As part of this work, two new concepts will be introduced: first, the idea of "tuning" a synthesized musical instrument, and second, the application of automatic tuning procedures by means of intelligent systems. If we consider the synthesis as a whole process which involves the reproduction of every aspect that determines the realistic sound of the musical instruments, tuning the synthesizer as a human expert does becomes meaningful