[2] Born Juan Antonio Orrego-Salas in Santiago on January 18, 1919, Orrego-Salas studied at the Conservatorio Nacional de Música (Chile), the music school of the University of Chile, in his native city where he was a pupil of Pedro Humberto Allende (composition) and Domingo Santa Cruz Wilson (composition).
During this period he studied music composition with Aaron Copland and Randall Thompson and musicology with Paul Henry Lang and George Herzog.
[2] In 1947 Orrego-Salas was appointed professor of music composition at the University of Chile; and was awarded the title Profesor Extraordinario at that institution in 1953.
[3] In 1961, Orrego-Salas permanently relocated to the United States to work at Indiana University Bloomington, where he co-founded the Latin American Music Center (LAMC).
One of his students at IU's Jacobs School of Music was composer Ricardo Lorenz who succeeded him as director of the LAMC.