As a result of the progress in information technologies, algorithms for sound generation and transformation are now ubiquitous in multimedia systems, even though their performance and quality is rarely satisfactory. For the specific needs of music production and multimedia art, sound models are needed which are versatile, responsive to user's expectations, and having high audio quality. Moreover, for human-machine interaction model flexibility is a major issue. We will review some of the most important computational models that are being used in musical sound production, and we will see that models based on the physics of actual or virtual objects can meet most of the requirements, thus allowing the user to rely on high-level descriptions of the sounding entities.