Tape loop

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Tape loops are loops of prerecorded magnetic tape used to create repetitive, rhythmic musical patterns. A measure of recorded 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 machine. Tape loop effects are often combined with glissando, a technique wherein the playback speed of the loop is increased or decreased over time.

Simultaneous playing of tape loops to create phase patterns and rhythms was developed and initially used by musique concrète and tape music composers, and was utilized by Steve Reich for his "phasing" pieces, and by Karlheinz Stockhausen.

Beginning in the late 1950s the BBC Radiophonic Workshop began using tape loops to add special effects to some BBC programming.

Pop musicians, most notably The Beatles, Can, and Pink Floyd, have used tape loops on their albums.

In the early 1970s, musicians Brian Eno and Robert Fripp created Frippertronics, a system for creating tape loops during a live performance. A few years later, Mission of Burma began using loops on their albums, and also began feeding snippets of vocals and guitar recorded moments earlier back into their live mix, thereby introducing live loop effects to punk rock. Experimental noise musician NON aka Boyd Rice played loops of speeches, radio broadcasts and conversations just under the threshold of comprehensibility in his live shows, starting in 1977. Since then, he's created loops to evoke a hypnotic, trance state in his audiences.

The length of the loop, of course, controlled the length of the repeated sound. On a standard reel-to-reel, one could loop, at most, a few seconds of music. Some were satisfied with this approach, but there were other methods to allow for longer loops. For example, one could place two reel-to-reel machines side by side and string the tape between them, using one machine for playback and the other simply as a sort of turnstile for the length of tape. By using this or other methods, some composers could create very long loops which allowed for lengthier fragments of sound. When recording his landmark 1978 ambient album Music for Airports, Brian Eno reported that for a particular song, "One of the tape loops was seventy-nine feet long and the other eighty-three feet." (Prendergrast, 123)

Digital sampling -- which can generally provide similar results with less effort -- overtook much tape loop use, beginning in the mid 1980s. Some musicians and composers, however, continue to use tape loops for various reasons.

An interesting direction of the evolution of the tape loop is the looping pedal - a digital sampler built into an easy-to-use footswitch-operated pedal of the kind most often used by guitarists to create looping layers of melody or texture during a live performance. A noteworthy example of this melodic layering effect is Ian Williams' dense, complex layers of guitar on Don Caballero's American Don (free MP3s available here and here). Some popular digital looping pedals (which can be used on any instrument, but are primarily used by guitarists) are the Line 6 DL4 (used by, among others, Jazz guitarists Bill Frisell and John Scofield), the Boomerang Phrase Sampler (used by Phish's Trey Anastasio), and the Boss Loop Station.