[anigbrowl]

I'm actually more impressed byt his one! You are right though, the one in the OP is heavily modulated by spectrographic data from the music. After effects include a crude plugin for this purpose, but the OP animation used a 3rd party one that is constrainable to a particular frequency window.

Apple's Motion is also very good in this area, including responding to MIDI which is a royal pain to achieve with AE - particularly annoying to me since I have several MIDI devices and would love to be able to generate keyframe data by twiddling knobs I already have. Ho hum...anyone know of dynamic midi resources for Javascript (ie not just passing a midi file to the audio driver)?