For the 2008 Glastonbury Festival we backed a giant interactive Pi, the filling? An awe struck audience.br br They asked: “If there is no beginning and no end, then what?” their answer, “Pi!” A 16 metre round Big Top tent in the festival’ Trash City area, that responded to the motion of the people within it.br br Stood inside, people were tracked by cameras, their silhouette projected on the walls. As they moved photons, plasmas and other particles radiated from them and were sent flying.br br Their movement also controlled sound as one of a series of instruments. Scratching a beat, playing a bass or strumming strings, the audience became composers, conductors and performers of their own collective experience.br br Go here for photos: flickr.com​photos​evangrant​sets​72157606029759739​br br Standing inside the Pi people were tracked by cameras and saw a silhouette of themselves on the walls of the space. As they moved photons, plasmas and other particles radiated from them and were sent flying around the space. Their movement also controlled sound as one of a series of instruments. Scratching a beat, playing a bass or strumming strings made the audience not only the filling but also the players, conductors and composers of their own collective Pi.br br Go here for photos: flickr.