He joined the orchestra in 1953. “Mr. Dreyfus was ‘at the center of the players’ labor activism during contentious years of disputes’ in the 1960s, his son said, which resulted in a long strike and, eventually, a 52-week contract. By the time of his retirement, he’d played under Stokowski, Ormandy, Muti, and his ‘personal favorite,’ Wolfgang Sawallisch.”