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.
Beginning in November, Stockhausen was able to work in the studio, but only recording and cataloguing natural sounds, mainly of percussion instruments.
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.
On the following day, the sorcery undespairingly continued: I changed my series, chose other sequences, cut other lengths, spliced different progressions, and hoped afresh for a miracle in sound.
[16] Durations are based on divisions of tape-length units of 216 cm, which comes to just about three seconds, but is a convenient number for reckoning subdivisions, since 23 × 33 = 216.