Page  151 ï~~MIT-Media Lab Dr. Neil Gershenfeld The cello provides a mature, responsive user interface with many continuous degrees of freedom and hence is an interesting system with which to explore the real-time control of electronic musical instruments. We will first review the physics of stringed instruments with an eye towards the role of the player's control inputs, and then describe the hardware that we have implemented to extract this gestural information from a cello (such as bow pressure and position). The range of values that we measure for these parameters and their usefulness as control parameters will be examined, and we close by considering the tradeoffs associated with the accuracy, reliability, price, and intrusiveness of the sensors. ICMC 151