This work, regarded by Swiss musicologist Jürg Stenzl as one of the central masterpieces of the 1950s, is a commemoration of the victims of Fascism, incorporating farewell letters written by political prisoners before execution. Musically, Nono breaks new ground, not only by the "exemplary balance between voices and instruments" but in the motivic, point-like vocal writing in which words are fractured into syllables exchanged between voices to form floating, diversified sonorities—which may be likened to an imaginative extension of Schoenberg's ""Klangfarbenmelodie" technique". Nono himself emphasized his lyrical intentions in an interview with Hansjörg Pauli,) and a connection to Schoenberg's "Survivor from Warsaw" is postulated by Guerrero. However, Stockhausen, in his 15 July 1957 Darmstadt lecture, "Sprache und Musik" (published the next year in the "Darmstädter Beiträge zur Neuen Musik" and, subsequently, in "Die Reihe"), stated: