 In 1966 Schaeffer published the book "Traité des objets musicaux" (Treatise on Musical Objects) which represented the culmination of some 20 years of research in the field of "musique concrète".In conjunction with this publication, a set of sound recordings was produced, entitled "Le solfège de l'objet sonore" (Music Theory of the Acoustic Object), to provide examples of concepts dealt with in the treatise.The development of musique concrète was facilitated by the emergence of new music technology in post-war Europe.