Combining Event and Signal Processing in the MAX Graphical Programming Environment

This paper describes how MAX has been extended on the NeXT to do signal as well as control computations. Since MAX as a control environment has already been described elsewhere, here we will offer only an outline of its control aspect as background for the description of its signal processing extensions. The main purpose for making electronic music production run in real time is so that a musician can exercise some sort of live control over the music. The problem of defining that control is a much harder one than that of defining the signal processing network which ultimately will generate the samples. The sample generation problem has historically been considered hard simply because of its stringent computational requirements. Today, a real-time programmable audio synthesis and processing engine can be bought at a price that researchers, and even some musicians, can pay. It is therefore not surprising that many systems are now being proposed for graphical signal network editing; recent ones are described in (Bate 1990), (Minnick 1990), and (Helmuth 1990). But the con1 trol problem, that of making the signal network respond in an instrument-like way to live human control, is not made appreciably easier by the availability of faster and faster hardware. Today, the challenge for a signal processing network editor is to open itself up to a wide range of control possibilities. To take complete control of all the possibilities of some kind of signal processing patch, or network, it may be necessary to specify independently where all the control is coming from: the basic pitch and tempo material, timbral changes, pitch articulation, whatever. These should be controllable physically, sequentially, or algorithmically; if algorithmically, the inputs to the algorithm should t...