Born into a musical family, Harry was the son of Harry Grant Sr., director at Bradenton High School from the 1920s-1940's and who helped to found the Florida Music Festival. Harry Jr, was a trombone player and graduate of his father's program in early 1930's and followed in his father’s footsteps into the field of Music and Music Education. After college, Harry performed nationally with the likes of Duke Ellington, Jack Teagarden, and the Ringling Bros. Circus Band. His first teaching position was at Lake Wales High School in 1937. He taught at Mulberry Consolidated School in the mid 1940's before moving on to Moore Haven High School from 1949-1952, Trenton High School from 1952-1959, and Suwannee County Schools from 1959-1965.
Mr. Grant took over the band program at Ocala High School in 1965 and remained until 1970. During his time, there were many changes happening, both in Ocala and for the band program. Mr. Grant took over after a brief period of membership decline and was able to slowly get the band program numbers back up from around 30 to around 70 members. He also added new components to the program such as a drill team, majorette corps, rock music club, and a swing band. These additions helped in diversifying the program beyond just the standard Drill Band and Concert Band format of the time. Mr. Grant also worked as an adjunct professor of music at the junior college in Ocala. He was the director for the Central Florida Junior College Community Band in addition to teaching music theory classes.
Across the nation, segregation and school integration were topics at the forefront of conversation and experience at the time. It was during Mr. Grant's tenure that integration orders came to Ocala schools and the band program found itself, once again, in the path of history as three of the first African-American students to attend Ocala High School were also members of the OHS Band Program. Mr. Grant was a vital part of creating a new identity for the OHS program that combined elements of Ocala High School band along with those of the Howard High School music programs. The School Board later made the decision to build a new school, not only to replace the aging Howard High facilities, but help facilitate a more equitable means to integrate Ocala schools. This new school would be considered the "vanguard" in social and educational integration in Ocala, hence the name, Vanguard High School. In 1969, while Vanguard High was under construction, Ocala High School hosted split sessions of classes for students of both schools until construction of Vanguard was completed. Mr. Grant ran both the Ocala High School program and, what would eventually become the following year, the Vanguard High School band.
Mr. Grant left Ocala at the end of the 1970 school year, moving to Fort Pierce where he began teaching at Westwood Jr High. In 1977, he received the FBA Outstanding Bandmaster Award (now known as the Oliver Hobbs Award). He retired from teaching in 1978. After 41 years of teaching, Mr. Grant remained a highly sought after clinician and adjudicator for Florida bands, and is fondly remembered by those active at the time as an incredible educator, storyteller, and musician. It is said that he could freely play, with mastery, any instrument in the room. Mr. Grant was later inducted into the Florida Bandmasters Association's Hall of Fame for his long career of outstanding teaching and dedication to Florida bands. The FBA middle school concert band Superior Award is named in his honor. He passed away in 1990.