Albert Einstein throws a party at his lakeside house at which he presents to his guests his latest invention: a time machine.So opens the opera Chronoplan, started in the late 1920s by the composer Julia Kerr, who took the score with her when she fled Nazi Germany with her family in early 1933, its planned premiere having been halted following Hitler’s takeover.The wider family story was chronicled in When Hitler Stole Pink Rabbit, an autobiographical novel by Kerr’s late daughter, Judith, in which passing references are made to her mother playing the piano. But Kerr’s reputation as one of the...