In the fifties, Mestres Quadreny was one of the first musicians to bring random music and computer-generated compositions to Barcelona. His ability to integrate a diverse range of artistic languages and to engage in constant experimentation led him to collaborate with some of the most important Catalan artists of his time, such as Joan Miró, Joan Brossa or Antoni Tàpies. Produced in a spirit of great creative freedom, Quadreny's pieces are meant to be seen as well as listened to. Self Service (1973) can only be performed with the participation of the members of the audience. L'estro aleatorio (1973-1978) was composed using lists of random numbers and consisting of musical structures of indefinite duration. And in Aronada (1971), the music is generated through a circular, target-shaped score with an indefinite duration.