Is it truth or fiction? Memoir or essay? Narrative or associative? To a writer like Michael Martone, questions like these are high praise. Martone's studied disregard of form and his unruffled embrace of the prospect that nothing--no story, no life--is ever quite finished have yielded some of today's most splendidly unconventional writing. Add to that an utter weakness for pop Americana and what Louise Erdrich has called a "deep affection for the...