The computer metasaxophone was developed by Matthew Burtner in 1999 at Stanford University's Center for Computer Research in Music and Acoustics. The inspiration for the metasax came while performing compositions such as Incantation S4, and Split Voices, pieces that involve slowly evolving musical textures made of long passages of sustained, complex sonorities. It became clear that, in the context of his style of music, a good deal of the performer's tactile sensitivity was being unused. While the saxophone allows for detailed control over embouchure changes and changing air pressures, the manual interface of the instrument has certain limitations. In particular, aside from the rapid change of key positions, the fingers of the performer have no direct control over the instrumental sound. By giving the keys pressure sensitivity or "aftertouch", a feature common on MIDI keyboard instruments, direct tactile control over the electronic signal processing could be given to the performer. This computer interface could be placed in the expressive zone left unused by the instrument, namely finger pressure on the keys. In essence, the saxophone keys which normally execute only on/off changes of the air column, are converted to continuous control levers. This initial realization led to a vision of seamless integration between the instrumental acoustic and instrumental electronic worlds. The performer could communicate an array of information from the body of the instrument by extending the instrument using sensing technology and embedded systems.

The metasaxophone tracks data from eight continuous controller force sensing resistors, triggers, and a two dimensional accelerometer chip. The force sensing resistors are located on the front B, A, G, F, E and D keys, and on the two thumb rests. Triggers are located on the bell of the instrument, and below each of the thumb rests. The accelerometer chip measures left/right, up/down tilt of the saxophone. The triggers on the body of the instrument may be used by the performer for applications such as playing samples from hard disc, starting and stopping processes, or managing program data/presets. The triggers on the bell of the instrument were designed to be visible to the audience while those below the thumb rests were designed for discrete operations.

The data from these sensors is collected via a 26 pin serial connector by a small computer fixed to the bell of the instrument. Pressure data from the performer is passed to the microprocessor through an RC circuit design. Trim potentiometers calibrate the sensitivity of each circuit. The metasaxophone operating system software converts the sensor data into MIDI messages. The circuit board and a 9-volt battery were fit into a black box with openings for the serial cable inputs, a MIDI output, and a power switch.  

The MIDI signal from the instrument allows for new aspects of performer control without hindering the acoustic saxophone sound in any way.

In addition to sending MIDI information, an electric saxophone system modification collects the audio signal through a specially designed microphone that captures subtle resonant properties within the instrument. Three electret microphones are mounted on bendable arms and they can be placed inside or around the instrument to pick up audio at different sound radiation points, inside or outside the instrument. The following figure shows the mounted microphone system. This image displays a common setup in which all three mics are positioned inside the instrument to capture the resonance of the instrument inside. This configuration is used in the Delta compositions described below. Each microphone has a separate output allowing the signal to be routed to different devices for external processing.