The Chilean composer Gustavo Becerra-Schmidt (1925-2010) has been considered one of the main twelve-tone composers in Chile. Especially during the 1950s he composed symphonic and chamber works that have attracted the attention of musicologists and theorists. During that decade he traveled to Europe to study the teaching of composition, becoming especially interested in the teaching of twelve-tone music. This paper studies the evolution of his pitch organization strategies between his trip to Europe (1955) and 1959, through the analysis of fragments of chamber works for solo instrument, trio and string quartet, postulating that a process of progressive assimilation and personal adaptation of the twelve-tone method in parallel with a critical reflection on the possibilities of the technique and its teaching as defended by European composers identified with the avant-garde, which would prompt him to seek new methods that transcend the serialism, maintaining the structural rigor that characterized said technique.