Unfolding in Switzerland between 1937 and 2002, Rose Tremain’s deeply moving thirteenth novel encompasses the Second World War, but history doesn’t drive the book’s events; rather, it guides them, throwing into relief Tremain’s themes of empathy, sacrifice, and betrayal. The Gustav Sonata (W.W. Norton, $26.95) is the story of lifelong friends who meet in kindergarten. They grow as close as brothers but each yearns for something he can’t get from the other. Gustav, whose father is dead, is the unloved son of an unwanted daughter. He craves his mother’s affection to her dying day—when he’s nearly sixty —learning how to “master” the pain of rejection by laughing instead of crying, which should be “easy,” since “laughing was a bit like crying. It was a strange convulsion; it just came from a different bit of your mind.” Anton, a musical prodigy for whom “the black grand piano open[ed] like an enormous heart, about to gather him in,” wants to be a concert pianist but suffers crippling stage fright and eventually, after decades of anguish, abandons his dream. Tremain depicts the boys, then the men, with great sympathy, as she does all her characters. Whether describing a passionate young woman, a lonely little boy, a man in an ethical quandary, or a frustrated artist, she writes about emotion with rare grace and insight. Like music, her elegant narrative captures the messiest human feelings and lets art transform them into something beautiful and nearly comprehensible.