In order for a performer to use these sensors, he must be seated in the chair, and thus coupled to the transmitting antenna. Other performers may also inject signal into the pickup antennas if they are touching the skin of the seated individual, thus becoming part of the extended antenna system. Before a show, the performer moves his hand around the perimeter of the sensor range, after which a linear least-squares fit produces a calibration that gives good tracking coordinates . These are used for changing parameters when the foot pedals are dedicated to generating musical sounds, or for instigating t riggers when the performer is not seated, hence is unable to use the sensors. The sensors are used to trigger and shape sonic events in several different ways, depending on the portion of the composition that is being performed.
Several modes produce audio events that are also sensitive to the velocity of the hands and feet.