 The "axe-cut junctions" were replaced with micrometric junctions and a whole new technique of production, less dependency on performance skills, could be developed.Tape editing brought a new technique called "micro-editing", in which very tiny fragments of sound, representing milliseconds of time, were edited together, thus creating completely new sounds or structures .During the GRMC period from 1951–1958 time Schaeffer and Jacques Poullin developed a number of novel sound creation tools including a three-track tape recorder, a machine with ten playback heads to replay tape loops in echo (the morphophone), a keyboard-controlled machine to replay tape loops at twenty-four 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 loudspeakers, including one hanging from the centre of the ceiling (the potentiomètre d'espace) .