It's an old question. It goes back as far as Bridge over Troubled Water, when Paul Simon gathered some unexpected, tropical-inflected rhythms around him and first really found his voice. His lyrical voice, that is: the tart, tempered combination of irony and melancholy that would turn him into one of the best writers of his generation, either in the grooves or on the page.
There have been, intervening, two decades, a couple of marriages, one son, a hurtful professional divorce and a group of exquisite albums. But that Troubled Water question, framed as an up-tempo goof but phrased suddenly like a...