Examples of ZIPI Applications

Abstract

The controller will work with any instrument, but for now assume that it is connected to a guitar with a hexaphonic pickup. (Hexaphonic means one output channel for each of the six guitar strings instead of the usual case in which the sound of all six guitar strings comes out of one output.) The controller will track pitch, loudness, even/odd balance, pitched/unpitched balance, and brightness information for each of the six strings of the guitar in real time, updating each parameter every 8 to 10 msec. It will also produce articulation information, noting when trigger and release events occur on each string. The built-in synthesizer will use sample playback and will be able to vary the pitch, loudness, even/odd balance, pitched/unpitched balance, and brightness of a sound. Thus the sounds produced by the synthesizer will be able to follow all these nuances of the acoustic sound, not just its pitch and volume. The intention is to give an instrumentalist such as a guitar player more expressive control over the sounds produced by a synthesizer. When the guitarist picks closer to the bridge, a synthesizer producing an organ sound would make it brighter. When the guitarist plays a 12th-fret harmonic, a trumpet sound would go up an octave and change to a quieter, more delicate timbre. When the guitarist partially mutes the strings with his or her palm, a saxophone sound would have a more breathy, noisy character. When the guitarist completely mutes the strings with the left hand and scratches rhythmically, a piano patch would produce just the sound of hammers hitting strings, with no pitched content. This instrument will use ZIPI to control an external synthesizer with the same high-bandwidth continuous control information that it uses internally. As the default configuration, the controller will send the information from each guitar string to a separate MPDL note address. It would be useful for these six MPDL notes to be in the same instrument; this would make it possible to control all of the guitar's synthesized sound with a single message, e.g., pan or amplitude. How much bandwidth does this require? Every 10 msec, the controller will send a ZIPI packet that looks like this: