Dexter Morrill was born in North Adams, Massachusetts in 1938. As a young musician he studied with Peter Fogg in North Adams and later with Professor Irwin Shainman at Williams College, who invited him to perform in the Berkshire Symphony Orchestra. After entering Colgate University in 1956 he studied composition with William Skelton, and in 1957 performed at the Lenox School of Jazz, where he studied arranging with William Russo and trumpet with Dizzy Gillespie.
During his college years he was active as a Jazz trumpeter and began arranging and composing. Morrill entered Stanford University in 1960, studying composition with Leonard Ratner and orchestration with Leland Smith. In 1962 he received a Ford Foundation Fellowship for the Young Composer's Project and was in residence at the University City, Missouri school system for two years. In 1964 Morrill continued his graduate studies at Cornell University, where he studied with composer Robert Palmer. In 1966 he received another composing grant for a residency at Kansas State Teachers College at Emporia. After teaching briefly at St John's University in New York he completed his doctoral studies in 1970.
Morrill returned to teach at Colgate University in 1969, and remained there until his retirement in 2001. Early performances included his Concerto for Trumpet and Strings with the Syracuse and Baltimore Symphonies (in Baltimore under a grant from the Rockefeller Foundation), and a commissioned work for Ruggiero Ricci, Three Lyric Pieces, premiered at Lincoln Center in 1970. His early String Quartet No 1 was also performed and recorded by the Madison String Quartet, then in residence at Colgate. Violinist Bruce Berg performed the Ricci pieces and recorded them for the Musical Heritage Society.
In 1970 Morrill visited Stanford and the Computer Music Group at the Powers Computer Laboratory in Mountain View, California, near the Stanford campus, and made a decision to build a computer music system at Colgate. In 1972 the Computer Music Studio became operational, and was located near the Digital Equipment Corporation PDP-10 at the Colgate Computer Center. Joseph Zingheim of Stanford built the digital/analog converter and several years later built a similar conversion devices for the IRCAM center in Paris, and the University of New Hampshire at Durham.
Most of Dexter Morrill's activity after 1972 was devoted to composition and teaching in the field of computer music, the study and synthesis of brass tones, using John Chowning's Frequency Modulation algorithm, which he expanded and elaborated for use in his compositions.
Morrill was indebted to his friend Chowning, and to Max Mathews and Jean Claude Risset, all early pioneers in this new field. Morrill published several articles in the Computer Music Journal (MIT Press) on his research, and received numerous performances of his computer music during the next twenty years. In 1976 Morrill converted the first complete set of trumpet tone recordings to digital form for analysis (NY Times/International Herald Tribune), and used these recordings for modeling his computer trumpet tones. He was a Guest Researcher at IRCAM in 1980, where he worked with two trumpeters from the Ensemble Inter-Contemporain to study musical phrasing (IRCAM papers).
The early Studies for Trumpet and Computer was perhaps his best known work of the mid 1970's. After 1976 Morrill concentrated on composing for solo instruments with computer generated accompaniment (using loudspeakers). In 1978 he collaborated with soprano Neva Pilgrim on a series of concerts entitled Singing Circuits in the U.S, Canada, Scotland and Austria. Pilgrim performed Six Dark Questions, based on a text by George Hudson, and music by Risset and others.
Pianist Dwight Peltzer recorded Morrill's Fantasy Quintet, composed under a grant from the National Endowment for the Arts in 1977. The Colgate studio also received
several NEA grants for a visiting composer program, with computer music workshops in the late 1970's.
For the next ten years the Colgate studio hosted many American and International composers, who also participated in concerts of this new music.
The National Endowment for the Arts also awarded Morrill a grant for his 1984 work, Getz Variations, composed for saxophonist Stan Getz. The first performance took place in an outdoor program at the Frost Amphitheater concerts, and later was performed by Getz in Berlin, sponsored by the German Government. Later in the 1980's Morrill worked with Wynton Marsalis on a proposed television project, which resulted in an interactive computer/trumpet design for the NEXT computer. Perry Cook, a brilliant young Stanford musician/engineer designed the system for this project.
Because of this work Morrill returned to performance and composed several pieces for himself which involved improvisation; the Sketches for Invisible Man and the Next Trumpet. His musician/composer colleagues Bruce Pennycook of McGill University, and Chris Chafe of Stanford also collaborated on new duo works for computer music performance in the United States, Canada, Argentina, Austria and Scotland. Morrill also performed frequently with soprano Pamela Jordan, who premiered his Walden Nocturnes and recorded his vocal music for the Centaur label. Morrill has composed several pieces for saxophonist David Demsey, who made the first commercial recording of the Getz Variations, and has become an important interpreter of his music. Since the late 1970s the composer has featured various forms of improvisation in his music, and in recently composed the Blanton Concerto for bassist Lynn Seaton. Morrill's interest in Jazz resulted in his Greenwood Press book The Music of Woody Herman, a Guide to the Recordings
After 1990 Dexter Morrill returned to composing music for conventional instruments and ensembles, and was active in recording. He composed several pieces for the Syracuse Symphony; the Iron Horse Concerto, Trombone Concerto and the Stained Glass Concerto, and chamber music for violinist Laura Klugherz, the Tremont String Quartet, flutist Karin Ursin and percussionist Rob Bridge. In 1995 he composed the Sea Songs for soprano Maureen Chowning, using Max Mathew's Radio Baton as a controller for voice processing.
Morrill is the author of the reference book The American String Quartet, A Guide to the Recordings. He has composed and recorded music with the Apple Hill Chamber Players, and his Fantasy Quintet was recently recorded by award winning pianist Lambert Orkis. In 2008, his seventieth birthday year, Morrill enjoyed a series of 'birthday concerts' in Chicago, Dallas and the San Francisco bay area. He lives with his wife Barbara in Hamilton New York.