While studying mathematics at the University of Strasbourg, Besançon and Lyon, Pierre-Alain Jaffrennou followed music studies at the conservatory and with private lessons, and in the electroacoustic class of Pierre Schaeffer at the National Superior Conservatory of Music in Paris. After these music studies, he became researcher for the Group of Music Research - ORTF - INA (GRM) where he created the computer music research laboratory. In 1981, with James Giroudon, he created Grame, national music creation center supported by the French Cultural Ministry. He is also professor with tenure in Arts and Techniques of Representation at the School of Architecture in Lyon, where he leads several research works about "Architecture and Computer Science".

His music works are varied : electroacoustic music, music with live electronic, instrumental music. His production is strongly marked by the contribution of computer in the process of music composition. He is also concerned with the space setting of the music in his work and its stagecraft. Particularly, he realizes important outdoor music shows with lot of means, and he creates sound and visual installations. His pieces are regularly played in France and abroad.

Some of his works were commissionned by public and private organizations, and Pierre-Alain Jaffrennou received the Award of the French Record Academy for the collective record "Grame-Musiques numériques" in 1989, The First Price for the national competition PUCE with the conception of SINFONIE, a sound spatialization system in 1984, The Golden Faust for his show "L'homme qui vole" (The Flying Man) presented in toulouse in 1991, The Bronze Faust in 1993 for "Jumelles", an opera co-written with James Giroudon, and in 1995, The Silver Faust for his video-movie "A voix basse" (In a low voice).