He studied composition and orchestral conduction at the National Conservatory of Music in Santiago. He also studied composition with Olivier Messiaen and orchestral conduction with Pierre Boulez.
He is perhaps best known for his long-term collaboration with director Raúl Ruiz. He has also worked with directors Patricio Guzman, Barbet Schroeder and Olivier Assayas. In 1972, the Guggenheim Foundation in New York awarded him a fellowship for his contribution in the field of electronic music
Arriagada has been living in France since 1966, working with experienced as well as promising directors while composing the scores of 44 of Raúl Ruiz"s films.
Over the years he has explored many different genres, including classical, contemporary and folk music as well as jazz and tango.