Inspired by: http://dry.ly/2010/10/17/create-a-music-visualizer-in-7-steps-with-ruby/ Requirements: Ruby-Processing (comes with jruby, processing, and minim) Soundflower http://code.google.com/p/soundflower/ MacOsX Setup: install jruby sudo gem install ruby-processing install soundflower via pkg launch Soundflowerbed SystemPreferences > Sound > Input set sound input to Soundflower If you have any issues, try playing with sound settings also in Audio MIDI Setup Run: rp5 run run_visualizer.rb