Complications from diabetes led to a cardiac arrest, according to Lora Martino, his wife of 36 years, who was traveling with him. Martino was 74.
Martino composed up until his death, spending his last morning working on a new Concertino for Violin and Fourteen Instruments, commissioned by the Tanglewood Music Center.
Martino's musical influences included the jazz clarinet training he received as a boy, twelve-note compositional techniques, and the music of Bart‹k and Milton Babbitt. He combined the twelve-note system with his own expressively intense style. His works were noted for being challenging and complex, but he resented being described as a serial or 12-tone composer.
Notable compositions include Notturno, a short chamber work that won the 1974 Pulitzer Prize, and his 1981 Fantasies and Impromptus, a work for piano divided into nine movements.
Martino was born in Plainfield, New Jersey, and studied clarinet, saxophone, and oboe as a boy. He also played in various bands as a teenager and began composing at 15. His college professors included Ernst Bacon, Babbitt, and Roger Sessions.
Martino's music is published by Dantalian, a publishing company he founded in 1978, and has been recorded on labels including Centaur and Koch.
According to the New Grove Dictionary of Music, "Martino's music has been characterized as expansive, dense, lucid, dramatic, romantic, all of which are applicable. But it is his ability...to conjure up for the listener a world of palpable presences and conceptions...that seems most remarkable."
Martino is survived by his wife, son Christopher, of Boston, and daughter Anna Maria Martino (from an earlier marriage), of Branford, Connecticut.