By Jenny Erpenbeck New Directions. 212 pp. $16.95 - - - "Not a Novel," the latest from Jenny Erpenbeck, bears the subtitle "A Memoir in Pieces," and yet it does not include much memoir, strictly speaking. Though this author's 2017 novel, "Go, Went, Gone," was greeted with acclaim, for the new selection of essays her American editors preferred a shorter selection than appeared in the original German. Thus the author's recollections of growing up in the Communist East, and of the upheavals that followed the Wall coming down - the memoir material, in other words - are confined to a brief opening section. That section is titled "Life," and indeed, the reminiscences have a crackling vitality. In one, the adult Erpenbeck at last gets to open her "Stasi file," the record kept by the now-defunct secret police, and there discovers middle-school love letters. In another her dead mother's old pressure cooker proves full of surprises. Both memories are expressed with masterful touches of repetition, achieving a telegraphic poetry. Nevertheless, the section comes to no more than a handful of pieces, a number of them only a couple of pages. Meatier by far is the group that follows, "Literature and Music." These investigations into Erpenbeck's joint calling (she directs opera, as well as writing novels) bristle with erudite allusion, not to mention sheer smarts. Repetition remains a hallmark of her style, but here it turns canny, yielding aphoristic gems: "Both literature and music are closely connected to ... silence, in their essence they are nothing but interpretations of ... silence, at least insofar as they aim to arrive at something like truth." She meditates on forebears from the Brothers Grimm to the late W.G. Sebald, and in the process illuminates fresh parallels between...