After Army service in Europe during World War II, he returned to Los Angeles. After a variety of jobs including one on an offshore ship casino, he enrolled in the School of Agriculture at the University of California before transferring to UCLA.
Between 1945 and 1950 Mantle Hood studied Western music under composer Ernst Toch and composed several classical pieces. Hood earned both his BA in music and MA in composition from UCLA in 1951. As a Fulbright scholar, Hood studied Indonesian music under Jaap Kunst at the University of Amsterdam.
He once said that upon his arrival in Java to do his doctoral research, he was not sure whether he would pursue composition or ethnomusicology (his trunk contained a large amount of blank music manuscript paper). He did decide on ethnomusicology, however, and wrote his Ph.D. dissertation on pathet, somewhat inadequately translated as the modal system of Central Javanese music. He proposed that the contours of the balungan (nuclear theme) melody are the primary determinants of the Javanese musical mode. The dissertation, The Nuclear Theme as a Determinant of Patet in Javanese Music was published in 1954.
After completing his doctoral work in 1954, Hood spent two years in Indonesia doing field research funded by a Ford Foundation fellowship. He joined the faculty at UCLA where he established the first gamelan performance program in the United States in 1958. He also founded the Institute for Ethnomusicology at UCLA in 1960. UCLA quickly became an important American hub of this rapidly developing field. Hood's work spawned a legion of teachers and leaders of the more than 100 gamelan groups in the United States today.
A renowned expert in Javanese and Balinese music and culture, Dr. Hood received honors from the Indonesian government for his research, among them the conferral of the title "Ki" (literally "the venerable") in 1986, and in 1992 was one of the first non-Indonesians to be honored with membership into the Dharma Kusuma (Society of National Heroes).
Hood wrote numerous novels, scholarly books and articles in journals and encyclopedias. Some of his works include The Ethnomusicologist (1971, 1982), Music in Indonesia (1972), the three-volumed The Evolution of Javanese Gamelan. He was fluent in French, German, Dutch, Italian and the Balinese and Javanese languages of the Indonesian islands.
In 1973, Hood left UCLA and retired to Hawaii where he composed music, wrote novels and served as an editor of The New Grove Dictionary of Music and Musicians. He was also wrote contributions for the Harvard Dictionary of Music and the Encyclopedie de la Musique.
In the 1980s, he came out of retirement in Hawaii to become Senior Distinguished Professor at the University of Maryland, Baltimore County, where he remained until 1996, establishing an ethnomusicology program modeled after that of UCLA. He was a professor of music at West Virginia University and a visiting professor at Harvard, Yale, Wesleyan, Indiana, and Drake Universities and the University of Ghana. He also served as President of the Society for Ethnomusicology from 1965 to 1967. In 1999 he was the Charles Seeger Lecturer at the annual conference of the SEM.
Mantle Hood was married twice. His second wife, Hazel Chung, was a teacher of Indonesian and African dance. Hood, with Chung, shot footage in Ghana and Nigeria for their film, Atumpan: The Talking Drums of Ghana (1964).
The inspiration of "bi-musical" was "bi-lingual". Hood applied the term to music the same way a linguist would when describing someone who spoke two languages. He also strongly proposed that ethnomusicology students should know the spoken language of the musical culture being studied. This led to the breakdown of the steadfast rule of having to have competence in French and German at many ethnomusicology programs. Now Javanese, Spanish and other languages can fulfill foreign language requirements.
"This emphasis upon music as communication, human understanding, and world peace, not only through musical performance, but also through research, teaching, and other forms of dissemination, is one of the greatest gifts Mantle Hood has given to ethnomusicology." (Encomium for Mantle Hood, Dale Olsen, SEM Newsletter, Vol. 39 No. 3, p. 4, May 2005).