John Adams said he learned that the Metropolitan Opera was scrapping plans to transmit his opera “The Death of Klinghoffer” to movie theaters around the world when the Met’s general manager, Peter Gelb, told him on Sunday by telephone that he had gotten “unimaginable pressure” from some Jewish groups that oppose the work. “I asked Peter if, before summarily canceling this, he would open it up to some kind of a public dialogue,” Mr. Adams recalled on Tuesday, in his first interview since the Met announced that it was dropping the opera, scheduled to appear this fall on its popular...