Etude (Stockhausen)  The Konkrete Etüde (Concrète Étude) is the earliest work of electroacoustic tape music by Karlheinz Stockhausen, composed in 1952 and lasting just three-and-a-quarter minutes. The composer retrospectively gave it the number "⅕" in his catalogue of works. In January 1952 Stockhausen travelled to Paris to study with Olivier Messiaen, and by March had become familiar with composers such as Pierre Boulez, Jean Barraqué, and Michel Philippot who were working with musique concrète at Pierre Schaeffer's Club d’Essai. Beginning in November, Stockhausen was able to work in the studio, but only recording and cataloguing natural sounds, mainly of percussion instruments. In December, at last, Stockhausen was allowed to make his own piece. Using sounds recorded from a prepared piano, he cut the tape into short pieces, spliced the pieces together, and superimposed the results . This involved taking the attack segment of each sound and repeating it to produce a relatively constant sound . The result was then transposed using a transposition machine called a "phonogène" . The entire process was accomplished in twelve days, concluded on 15 December 1952 . It was the first piece by a non-French composer made in the Paris studio . Even before completing the piece, Stockhausen was becoming disillusioned with musique concrète , and in a letter to Henri Pousseur written only a few months later, Stockhausen described the "Etude" as a "negative result" . Long thought to have been lost, the tape of the "Etude" was, according to one source, rediscovered by Rudolf Frisius ; according to another, it was found by the composer himself, "in a pile of old tapes" . Even after its rediscovery, Stockhausen did not permit the work to be published until 1992 . There are references to another, earlier and possibly unrealised "musique concrète" project, "Studie über einen Ton" (Study on One Sound), in two parts . However, this same title, only in French—"Étude sur un seul son"—had been used by Boulez for the first of his two concrète études, realised in 1951. Pierre Schaeffer, in an interview conducted many years after the fact, refers to both of these works by the same title and recalled that the tape of Stockhausen's "Study on One Sound" was only about 50 centimeters long—lasting less than one second at 76.2 cm/s. .