Buenaventura held various positions as a musician and faculty member from different universities and organizations. He served at the UP Conservatory of Music for 15 years as a faculty member (1930-1935), professor, and college secretary (1935-1939), and a member of the UP President’s Advisory Committee on Folk Songs and Music (1935-1938). He continued his service at the University as a professorial lecturer from 1946 to 1961.
In 1939 he was appointed as a music instructor and band conductor at the Philippine Military Academy, which brought him to his ambition of joining the military to serve the country. He became the director of different schools of music: San Pablo Music Academy (1942-1944), Conservatory of Music at the University of Santo Tomas (1961-1964), and the School of Music and the Arts at the University of the East (1964-1981), which he founded.



Major General Basilio Valez, then Secretary of National Defense, designated him to reorganize the pre-war Philippine Constabulary Band in 1945. He also became a co-conductor of the Municipal Symphony Orchestra of Manila, which toured the Far East and Hawaii in 1948, and Chief of Bands and Music of the Philippine Army in 1958-1961. In 1959, he founded the Manila Philharmonic Orchestra. He retired from military service in 1961 with the satisfaction of restoring one of the finest military bands in the world, the Philippine Constabulary Band.



He was also an active member of various professional organizations: the UNESCO National Commission of the Philippines (1961-1964), Executive Committee in Balikbanda of San Miguel Corporation (1984-1988), and the Asia League of Composers (1970–1988). From 1961 to 1968, he was designated as President of the National Music Council of the Philippines, UNESCO, and Vice President of the League of Filipino Composers from 1958 to 1988.
List of Bands Conducted
- Six-Piece Band, Baliuag Intermediate School, 1923
- UP ROTC Band, 1927-1929
- Banda Kasarinlan, Pasay City, 1931
- Field Artillery Band, Camp Dau, Pampanga, 1939
- Philippine Military Academy Band, 1931-1941
- Philippine Constabulary Band (currently Philippine Army Band) 1945-1961
- As guest conductor, The United States Maritime Band, Washington D.C., February 1949
- As guest conductor, Duke University Band, during the annual convention of the American Bandmasters Association held at the Charlotte, North Carolina, March 1949
- As guest conductor, the United States Military Academy Band, West Point, May 8, 1949
- As guest conductor, Ohio State University Band, May 1949
- As guest conductor, Kosei Wind Ensemble, during the annual convention of the Southeast Asia Band Directors’ Association, Tokyo, Japan, 1978 and 1980.
List of Orchestra Conducted
- Manila Symphony Orchestra (as assistant conductor under Dr. Herbert Zipper) 1945-1948
- Philippine Constabulary Concert Orchestra, 1945-1961
- Municipal Symphony Orchestra of Manila (as co-conductor) 1948
- Manila Philharmonic Orchestra, 1955-1964