It doesn't sync to live audio it records/grabs. It uses the Spotify API that provides rythmn/intensity mappings for most (all?) songs. So basically the web page asks the API which song you're currently playing on Spotify and what BPM it has and it renders the visualization accordingly.
grishka|3 years ago
It's a WebGL port of the Winamp visualizer.
sitkack|3 years ago
klingt-net|3 years ago
elaus|3 years ago
Minor49er|3 years ago