Despite the advanced tonal language of Intolleranza, the political message of the opera was directed not only to the bourgeois audience. To Nono, it was important that his works were adopted by all social classes: in 1962 he organized the first of many discussion concerts which featured his music. Held in Italian factories, the concerts attracted up to 5,000 visitors. To make sure that his works were understood by the Italian workers, Nono also used sounds and noises for his electronic compositions which he had recorded in factories