Pierre Schaeffer (1910-1995) was a French composer, acoustician and electronical engineer. In 1948, while working at Radiodiffusion et Télévision Françaises, he initiated "concrete music", which was based on using sounds existing in the environment as the musical material, by recording, processing and combining them into a musical form.
The means of manipulation he used included changing the playback speed to change the pitch, playing the tape backwards, cutting the tape for precise duration control, filtering or amplifying certain frequencies of the sound waves, and other more complex methods.
The first important piece of concrete music was the Symphonie pour un homme seul (Symphony for a Lonely Man) composed in 1950 by Schaeffer in collaboration with Pierre Henry. This and other works of concrete music reflect the approach to sound that had a significant impact on electronic music makers in later years. His other works include the experimental opera Orpheé 53 (1953). In the years 1968 to 1980 he taught electronic composition at the Paris Conservatory.