A full Westminster Cathedral for the RCO's nine-organ extravaganza, including Guillou's La revolte des orgues, earlier this month | photo Simon Jacobs Jean Guillou was a composer, improviser and performer frustrated by the lack of vision for the future of the organ as an instrument.  He dreamed of an instrument that could escape both religion and the church, consisting of small individual modules which could be placed around and among an audience, in a hall or in the open air. In 2005 this concept inspired his futuristic organ design for the Auditorio de Tenerife, with eight…