Leo Kupper was born in Belgium in 1935. He worked with Henri Pousseur at the first electronic music studio in Belgium and is founder and director of the Studio de Recherches et de Structurations Electroniques Auditives in Brussels. The works on Electro-Acoustic are Electro-Acoustic Santur (1989), for 2 santurs, 4 micro-processors and electronic sounds. Guitarra Cubana (1988) is presented in the form of 3 sequences. The first two sequences combine guitar sounds and phonetic sounds, the last one uses only guitar sounds. Inflexions Vocales (1982) with Françoise Vanhecke (soprano) is a vocal composition for soprano with accompaniment by a stereo tape. The final work is Le Reveur au Sourire Passager (1977) with Jean-Claude Frison (reciter). La composition, à travers le poème, décrit un monde obscur, profond, incompréhensible et mystérieux.