Gerard Schwarz, conductor
Update: You might read that David Diamond's music was shoved aside due to the mythological dominance of serial composers in the 1950s to some unspecified date. That is utter bull shit. I was in school for a good part of that time and it was nothing I ever heard or saw. If I had the time and resources I'd analyze the concert programs of orchestras and performing groups to come up with some hard numbers. I would like someone to point to the major orchestras in the United States and anywhere which stopped programming tonal compositions as the vast majority of the pieces they performed during those years. I doubt that even in the universities where the serialists are alleged to have held power didn't program many times more tonal compositions than serial compositions. There may have been reasons that performances of tonal composers' new pieces weren't programmed as often as they got used to in the 1930s and 40s but it was not because those performance slots were all filled by serial compositions.
It's not an unknown phenomenon in music for the work of even a very fine composer to go into eclipse only to be revived later, often well after the composer died. Some composers never are appreciated during their lifetime. The early 20th century avant garde composers sometimes didn't get to hear their music in the form they heard it in their minds. Even some compositions by well known tonal composers didn't get a performance during the composers lifetime. George Whitefield Chadwick's opera The Padrone, one of his major works, wasn't performed until 1995, 64 years after he died.
Even David Diamond admitted that one of his problems in that regard could be due to his very difficult personality, he was infamous for getting into fights with conductors who were rehearsing his music. I don't recall which one banned him from rehearsals for that reason.