"What results [from the compositional system of Boulez's Structures] can only be described as composition by numerology. The possiblities are endless; a computer could be programmed to put down notes according to this prescription and in a very short time could turn out enough music to require years for its performance. By using different numerical rules -- using a knight's move, for example, rather than a bishop's move along the diagonals — music for centuries to come could be produced."