Blind Test stradivarius copy concealed within a wall, 2009. The Stradivarius is interesting to Simon Gush because of his search for the idea of an ultimate instrument. He feels that the place it holds in popular imagination makes it an icon of excellence. A further part of the mystique that it holds in popular culture is the dream of discovering one (due to the fact that only up to seven hundred instruments are thought to have been made and the whereabouts of far less of them are known, although most were probably destroyed over the last three hundred years). The seductive idea persists that, at anytime and in the most unusual place, one might still find one. Another key aspect of my fascination with these violins is the idea that, in a blind test, they are often indistinguishable from other violins of the same quality. Similarly, computer testing has been unable to give us the answer as to what the precise reason is for the crucial difference that it has over its competition. This, for me, seems to hold a promise of an idea of a quality that is elusive and impossible to pinpoint.