… alluding, of course, to Pärt’s pivotal 1976 work Sarah Was Ninety Years Old. The ninetieth birthday of the monumentally singular Estonian composer, which fell on September 11, will be celebrated at Carnegie Hall with a pair of concerts in October and again in December when Gidon Kremer, one of his most steadfast advocates, plays in his honor. Especially seductive is the prospect of hearing Pärt’s explosive 1968 piece Credo. Paavo Järvi will lead the Estonian Festival Orchestra and the Estonian Philharmonic Chamber Choir; the same forces play the work on a new Alpha Classics recording. Neeme Järvi, Paavo’s father, led the première, which created a sensation and drew the ire of the Soviet authorities. “Arvo was, for me and my sister, my father’s hip friend,” the younger Järvi says. “He wore a baseball cap, jeans, and a denim jacket.”