Yehuda "Julek" Nir was 11 years old when his father was taken away from the family in 1941. The Nirs went on to wander Poland disguised as Catholics. Gottfried Wagner, great-grandson of the monumental opera composer Richard, was born after WWII to the musical family notorious for its anti-Semitic and later pro-Nazi stance. Today, Wagner and Nir are psychiatrists as well as friends, and Wagner is a passionate proponent of dialogue between victims and Nazi progeny. Conversations between the two serve as the basis for an opera, ironically enough, which premieres Sunday night in Jaffa. Entitled Lost Childhood, it is composed by Janice Hamer, and its libretto - by Mary Azrael - takes place over a period of several days at a professional convention, where the German psychiatrist's questioning opens the survivor's long-supressed floodgate of memories. A strong bond develops between the two as they face the past and their complex, unexpected feelings toward each other. The 16-character opera will be sung in English with Hebrew surtitles. Merkaz Hamusika, 10 Rehov She'arit, Jaffa, (03) 521-5200, NIS 90.