Tape loop

In music, tape loops are loops of magnetic tape used to create repetitive, rhythmic musical patterns or dense layers of sound when played on a tape recorder. 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. Popular music authors of 1960s and 1970s, particularly in psychedelic, progressive and ambient genres, used tape loops to accompany their music with innovative sound effects. In the 1980s, analog audio and tape loops with it gave way to digital audio and application of computers to generate and process sound. In a tape loop, a section of magnetic tape is cut and spliced end-to-end, creating a circle or loop which can be played continuously, usually on a reel-to-reel tape recorder, making the sound repeat endlessly. Simultaneous playing of tape loops to create patterns and rhythms was developed and initially used by musique concrète and tape music composers, and was most extensively utilized by Steve Reich for his "phasing" pieces such as "Come Out" (1966) and "It's Gonna Rain" (1965), and by Karlheinz Stockhausen in Gesang der Jünglinge (1955–56) and Kontakte (1958–60). Stockhausen also used the technique for live performance in Solo (1965–66). If, instead of simply playing back a recorded loop, something is done to progressively alter the recorded material between cycles, such as re-recording the sound before it passes the playback head or adding new material to the loop, then a process of change will occur in the content, quality and complexity of the material. On a standard reel-to-reel tape recorder, one loop can be no more than few seconds long. Some composers were satisfied with this approach, but there were other methods to allow for longer loops. For example, placing two reel-to-reel machines side by side with the tape path running from the one to the other.