Musically gifted from an early age, he started his first orchestral piece at eleven and completed his first symphony (out of nine he would eventually write) before his 19th birthday.
His Third Symphony, finished the day he turned 23 and initially written for his PhD requirements at Eastman, immediately catapulted him to music prominence.
The work was performed by the New York Philharmonic the following year, and it led Mennin's appointment to the composition faculty of The Juilliard School.
The centenary of his birth was marked by the world premiere of the Aria from his unfinished Violin Concerto at the Aspen Music Festival in August 2023.
[3] His notable students include Van Cliburn, Jacob Druckman, Richard Danielpour, Karl Korte, Charles L. Bestor, Jack Behrens, and Claire Polin.