The MATRIX (Multipurpose Array of Tactile Rods for Interactive eXpression) is a new musical interface for amateurs and professionals alike. It gives users a 3- dimensional tangible interface to control music using their hands, and can be used in conjunction with a traditional musical instrument and a microphone, or as a stand-alone gestural input device. The surface of the MATRIX acts as a real-time interface that can manipulate the parameters of a synthesis engine or effect algorithm in response to a performer's expressive gestures. One example is to have the rods of the MATRIX control the individual grains of a granular synthesizer, thereby "sonically sculpting" the microstructure of a sound. In this way, the MATRIX provides an intuitive method of manip