Gehlhaar was the son of a German rocket scientist, who emigrated to the United States in 1953 to work at a rocket-development research centre in New Mexico. Although he took an interest in music from the age of eight or younger, in the post-war years the family could not afford for him to learn an instrument, and so Rolf only began to play the piano at the age of fifteen, and at about the same time began to compose for fun. He took American citizenship in 1958 and studied at Yale University and the University of California, Berkeley. Initially, he had studied medicine, but soon changed his major to philosophy and the philosophy of science; then at Yale he attended a course in composition, which was an arousing experience. He moved to Cologne, Germany in 1967 to become assistant to Karlheinz Stockhausen, and became a member of his performing ensemble. In 1969, together with Johannes Fritsch and David C. Johnson, he founded the Feedback Studio, Cologne, a new-music performance center and publishing house. He later moved to England, where he became in 1979 a founding member of the Electro-Acoustic Music Association of Great Britain. In 2002 he Became Senior Lecturer in Design and Digital Media at Coventry University; at the time of his death he was Professor in Experimental Music at Coventry University, School of Art & Design. He also was a founding member of the British Paraorchestra and its technical director. His works are for both acoustic and electro-acoustic media, though he is best known for his work with computer-controlled composition, and for his interactive installations such as Sound=Space, HeadSpace, CaDaReMi, Walking on Earth, and has for many years collaborated with Luis Miguel Girao of Artshare, Aveiro, Portugal. He died in London on 7 July 2019.
Gehlhaar, R., Girao, L. M., Rodrigues, P., Penha, R. "Instrument for Everyone: Designing New Means of Musical Expression for Disabled Creators" Casa da Musica, Porto; DRHA 2010 Conference Proceedings, Brunel University 2010
Gehlhaar, R., Girao, L. M., Rodrigues, P. M., "CaDaReMi, an Educational Game", ICDVRAT Intl Journal for Disability and Human Development 2010.
Gehlhaar, R., Girao, L. M., Rodrigues, P. M., Almeida, A. P., 2008. "Musical Topologies in Sound=Space". In 28th ISME World Conference. Bologna, Italy,
Almeida, A. P., Girao, L. M., Gehlhaar, R. and Rodrigues, P. "SOUND=SPACE Update at Casa da Musica". In Proceedings of 2nd European Conference on Development Psychology of Music Perception , Roehampton University, 80-84.
Almeida, A. P., Girao, L. M., Gehlhaar, R. Rodrigues, P., Neto, P. and Monica M. "SOUND=SPACE OPERA". in Proceedings of 7th International Conference on Disability Virtual Reality and Associated Technologies with ArtAbilitation, ICDVRAT/University of Reading, 347-354.
Gehlhaar, R., Rodrigues, P., Girao, L, "Cybersong Nime’05, May 26–28, 2005". Vancouver, BC, Canada.
Selected exhibitions & performances
SONG for alto Saxophone, Aveiro, Portugal 2012
VIAGEM, orchestral composition for 80 disabled musicians, premiered April 2010 at Casa da Musica, Porto, Portugal