Electricity Comes From Other Planets
Fred and James wrote a song that was designed to have 8 parts, then we designed 8 "planets", one for each part, which we had CNC'd, then I created some custom software (mostly based off previous projects) to project animations onto them.
The animation system was in realtime - ableton live piped out midi which went over the network, then I made a sort of pseudo-scripting language in C++ where I could trigger different effects on the inidividual faces of a planet depending on which note is played (with as few lines of code as possible!) Most of the work for this job was listening to the invidual parts and trying to make each planet 'dance' to the music.
To interact with each planet, you get closer or further away from it, and it influences the music. We used 2 kinects on the ceiling, and they seemed to work fine over 6 metres (no natural light though).