Editing Musique concrète (section)

===Development of novel devices===
During the GRMC period from 1951 to 1958, Schaeffer and Poullin developed a number of novel sound creation tools. These included a three-track [[multitrack recording|tape recorder]]; a machine with ten playback heads to replay tape loops in echo (the morphophone); a [[music keyboard|keyboard]]-controlled machine to play tape loops at preset speeds (the keyboard, [[chromatic]], or ''Tolana phonogène''); a slide-controlled machine to replay tape loops at a continuously variable range of speeds (the handle, continuous, or ''Sareg phonogène''); and a device to distribute an encoded track across four [[loudspeaker]]s, including one hanging from the centre of the ceiling (the ''potentiomètre d'espace'').<ref name="Palombini-1999"/>

====''Phonogène''====
[[File:Phonogene.jpg|upright|thumb|right|The chromatic phonogène]]
Speed variation was a powerful tool for sound design applications. It had been identified that transformations brought about by varying playback speed lead to modification in the character of the sound material:
* Variation in the sounds' length, in a manner directly proportional to the ratio of speed variation.
* Variation in length is coupled with a variation in [[Pitch (music)|pitch]], and is also proportional to the ratio of speed variation.
* A sound's attack characteristic is altered, whereby it is either dislocated from succeeding events, or the energy of the attack is more sharply focused.
* The distribution of spectral energy is altered, thereby influencing how the resulting timbre might be perceived, relative to its original unaltered state.
The phonogène was a machine capable of modifying sound structure significantly and it provided composers with a means to adapt sound to meet specific compositional contexts. The initial phonogènes were manufactured in 1953 by two subcontractors: the chromatic phonogène by a company called Tolana, and the sliding version by the SAREG Company.<ref name="Poullin-1999">{{harvp|Poullin|1999}}</ref> A third version was developed later at ORTF. An outline of the unique capabilities of the various phonogènes can be seen here:

*'''Chromatic''': The chromatic phonogène was controlled through a one-octave keyboard. Multiple capstans of differing diameters vary the tape speed over a single stationary magnetic tape head. A tape loop was put into the machine, and when a key was played, it would act on an individual [[pinch roller]] / [[Capstan (tape recorder)|capstan]] arrangement and cause the tape to be played at a specific speed. The machine worked with short sounds only.<ref name="Poullin-1999"/>
*'''Sliding''': The sliding phonogène (also called continuous-variation phonogène) provided continuous variation of tape speed using a control rod.<ref name="Poullin-1999"/> The range allowed the motor to arrive at almost a stop position, always through a continuous variation. It was basically a normal tape recorder but with the ability to control its speed, so it could modify any length of tape. One of the earliest examples of its use can by heard in ''Voile d'Orphée'' by Pierre Henry (1953), where a lengthy [[glissando]] is used to symbolise the removal of [[Orpheus]]'s veil as he enters hell.
*'''Universal''': A final version called the universal phonogène was completed in 1963. The device's main ability was that it enabled the dissociation of pitch variation from time variation. This was the starting point for methods that would later become widely available using digital technology, for instance [[Audio timescale-pitch modification|harmonising]] (transposing sound without modifying duration) and [[Audio timescale-pitch modification|time stretching]] (modifying duration without pitch modification). This was obtained through a rotating magnetic head called the Springer temporal regulator, an ancestor of the rotating heads used in video machines.

====Three-head tape recorder====
This original tape recorder was one of the first machines permitting the simultaneous listening of several synchronised sources. Until 1958 musique concrète, radio and the studio machines were [[monaural|monophonic]]. The three-head tape recorder superposed three magnetic tapes that were dragged by a common motor, each tape having an independent [[Bobbin|spool]]. The objective was to keep the three tapes synchronised from a common starting point. Works could then be conceived [[polyphonic]]ally, and thus each head conveyed a part of the information and was listened to through a dedicated loudspeaker. It was an ancestor of the multi-track player (four then eight tracks) that appeared in the 1960s. ''Timbres Durées'' by Olivier Messiaen with the technical assistance of Pierre Henry was the first work composed for this tape recorder in 1952. A rapid rhythmic polyphony was distributed over the three channels.<ref name="Teruggi-2007-p218">{{harvp|Teruggi|2007|p=218}}</ref>

====Morphophone====
[[File:Morphophone.JPG|upright|thumb|left|The Morphophone]]
This machine was conceived to build complex forms through repetition, and accumulation of events through [[Delay (audio effect)|delays]], filtering and [[feedback]]. It consisted of a large rotating disk, 50&nbsp;cm in diameter, on which was stuck a tape with its magnetic side facing outward. A series of twelve movable [[tape head|magnetic heads]] (one each [[recording head]] and erasing head, and ten playback heads) were positioned around the disk, in contact with the tape. A sound up to four seconds long could be recorded on the looped tape and the ten playback heads would then read the information with different delays, according to their (adjustable) positions around the disk. A separate [[amplifier]] and [[band-pass filter]] for each head could modify the [[sound spectrum|spectrum]] of the sound, and additional feedback loops could transmit the information to the recording head. The resulting repetitions of a sound occurred at different time intervals, and could be filtered or modified through feedback. This system was also easily capable of producing artificial reverberation or continuous sounds.<ref name="Teruggi-2007-p218"/>

====Early sound spatialisation system====
[[File:Pierre Henry in concert, 1952.jpg|thumb|right|[[Pierre Henry]] using induction coils to control sound spatially]]
At the premiere of Pierre Schaeffer's ''Symphonie pour un homme seul'' in 1951, a system that was designed for the spatial control of sound was tested. It was called a ''relief desk'' (''pupitre de relief'', but also referred to as ''pupitre d'espace'' or ''potentiomètre d'espace'') and was intended to control the dynamic level of music played from several shellac players. This created a [[stereophonic]] effect by controlling the positioning of a [[monaural|monophonic]] sound source.<ref name="Teruggi-2007-p218"/> One of five tracks, provided by a purpose-built tape machine, was controlled by the performer and the other four tracks each supplied a single loudspeaker. This provided a mixture of live and preset sound positions.<ref>{{harvp|Poullin|1957}}</ref> The placement of loudspeakers in the performance space included two loudspeakers at the front right and left of the audience, one placed at the rear, and in the centre of the space a loudspeaker was placed in a high position above the audience. The sounds could therefore be moved around the audience, rather than just across the front stage. On stage, the control system allowed a performer to position a sound either to the left or right, above or behind the audience, simply by moving a small, hand held transmitter coil towards or away from four somewhat larger receiver coils arranged around the performer in a manner reflecting the loudspeaker positions.<ref name="Teruggi-2007-p218"/> A contemporary eyewitness described the ''potentiomètre d'espace'' in normal use:

<blockquote>One found one's self sitting in a small studio which was equipped with four loudspeakers—two in front of one—right and left; one behind one and a fourth suspended above. In the front center were four large loops and an ''executant'' moving a small magnetic unit through the air. The four loops controlled the four speakers, and while all four were giving off sounds all the time, the distance of the unit from the loops determined the volume of sound sent out from each.<br>The music thus came to one at varying intensity from various parts of the room, and this ''spatial projection'' gave new sense to the rather abstract sequence of sound originally recorded.<ref>{{harvp|Gradenwitz|1953}}</ref></blockquote> The central concept underlying this method was the notion that music should be controlled during public presentation in order to create a performance situation; an attitude that has stayed with acousmatic music to the present day.<ref name="Teruggi-2007-p218"/>