This program takes audio input from where ever the computer does (usually the microphone). A ball bouncing around in the window (not unlike the screensaver DVD players use) changes color based on which wall it has recently touched, and its diameter at any given time is a function of the volume of the audio input stream. I left some examples where the input were different pieces of music below.
Nothing too earth shattering here, but its cool to see dynamics mapped out in time. If a recording has hits, swells, or a really strong 2 and 4, it pops out at you; its especially fun to watch live.