130 seconds of a music visualization engine and generative drawing built in AS3 using particles and physics engine. See the whole thing here: christeso.com/labs/actionscript-3-sound-visualization-generative-drawing.asp

512 particles are released with instructions to disperse randomly throughout the scene. Variants include friction and wander. Particle location is constantly tracked and more particles are drawn at that location. These particles are sized and alpha'd according to stage location creating a "corridor".

Music visualization occurs by looping through SoundMixer.computeSpectrum and creating a ByteArray. Each of the 512 particles are controlled the ByteArray which conveniently contains 512 bytes of data. Each byte contains a floating-point value. This value determines the individual particles scale and glow.

Music: All Mine | Portishead