We now turn to the main subject of this book, physical models of musical instruments and audio effects. In contrast to the non-physical signal models mentioned above, we will consider a signal model to be a physical signal model when there is an explicit representation of the relevant physical state of the sound source. For example, a string physical model must offer the possibility of exciting the string at any point along its length.
We begin with a review of physical models in general, followed by an overview of computational subtypes, with some indication of their relative merits, and what is and is not addressed in this book.