Tape loop

Originating in the 1940s with the work of Pierre Schaeffer, they were used among contemporary composers of 1950s and 1960s, such as Éliane Radigue, Steve Reich, Terry Riley, and Karlheinz Stockhausen, who used them to create phase patterns, rhythms, textures, and timbres.

[2] The longest open tape loop ever created was made by Barry Anderson for performances of Stockhausen's Solo,[3] but closed cartridges commonly make much longer lengths available.

In the late 1940s, Pierre Schaeffer used special phonograph discs with a sillon fermé (closed groove) to repeat segments of sounds in his musique concrète studio in Paris.

[6] In 1955, Éliane Radigue, an apprentice of Pierre Schaeffer at Studio d'Essai, learned to cut, splice and edit tape using his techniques.

She composed several pieces (Jouet Electronique [1967], Elemental I [1968], Stress-Osaka [1969], Usral [1969], Ohmnht [1970] Vice Versa, etc [1970]) by processing the feedback between two tape recorders and a microphone.

[11] At this same time in Cologne, Karlheinz Stockhausen produced a more ambitious work, Gesang der Jünglinge (1955–56), which made extensive use of tape loops, particularly for its stratified impulse groups and choral swarms.

With assistance of Richard Maxfield and Ramon Sender, Riley combined tape loops with echoplex devices, producing an "acid trip" piece Mescalin Mix (1961), made from sound samples from his earlier works.

Another dub producer, Sylvan Morris, developed a slapback echo effect by using both mechanical and handmade tape loops.

Later on, Gavin Bryars explored a similar concept in composition 1, 2, 1-2-3-4 (1971), played by a small ensemble in which every musician independently tried to reproduce tape recording.