what is meant by musique concrete used by stockhausen

Musique concrète is a type of music composition that utilizes recorded sounds as raw material. It is an experimental technique of musical composition that involves mixing recorded sounds, including acoustically produced tones and sounds, with sounds derived from the natural environment, voice, and musical instruments. Compositions in this genre are not restricted to the normal musical rules of melody, harmony, rhythm, meter, and so on. The theoretical basis of musique concrète as a compositional practice was developed by French composer Pierre Schaeffer beginning in the early 1940s. The technique exploits acousmatic sound, such that sound identities can often be intentionally obscured or appear unconnected to their source cause. Karlheinz Stockhausen was a German composer who was known for his pioneering work in electronic music, including musique concrète. In his compositions, Stockhausen used musique concrète techniques to manipulate and arrange "concrete" sounds.