English-born U.S. organ designer and builder, who designed or extensively rebuilt many of the largest and finest instruments of the 20th century.

Although he studied organ as a boy, Harrison began his career as an engineer. In 1912 he passed the qualifying examination of the Chartered Institute of Patent Agents and joined his father's firm. In 1914 he began work as patent attorney for Henry Willis & Sons (organ builders). Upon his return from military service he acted as an assistant to Willis, studied voicing methods, and, with his growing reputation as an organ designer and craftsman, was elevated to a directorship.

Harrison left Willis in 1927 to join the Aeolian-Skinner Organ Company of Boston, a company with which he remained for 29 years. In 1933 he became technical director of the company, in charge of the mechanical and tonal design of all instruments, and in 1940 he was elected president and treasurer. He continued to have a great influence on the development of voicing and tone-production throughout the industry.

Among the best known examples of his work are the organs at the Cathedral of St. John the Divine and Riverside Church, New York City; the Mother Church and the First Church of Christ, Scientist, Boston; and the Mormon Tabernacle, Salt Lake City, Utah.