BOSTON , MA -- Robert "RZ" Zildjian, founder of the Sabian Inc. musical cymbal manufacturing company, has died. He was 89. Sabian announced Zildjian's death on its website Thursday. The firm was closed until Monday and the company announcement had no details about his death. Zildjian founded Sabian in 1981 after a legal battle with his brother, Armand, over their inheritance of the family business, Avedis Zildjian Co., a major cymbal maker. The companies remain competitors. The family's U.S. business was founded in the Boston area in 1928 by their father, Armenian immigrant Avedis Zildjian, and a great-uncle. The rock `n' roll era brought an expanding demand for its percussion products. RZ Zildjian began working for his father as a teenager and set up a subsidiary, AZCO, in Meductic, New Brunswick, Canada, in 1968.