The first sign that the Wilder marriage might be in trouble happened before the wedding: it was a knock-down, drag-out fight about whether there's a fundamental difference between music in the European art music tradition and music in the American blues tradition. (We can all agree that this is a severely nerdy topic to fight about.) Eventually, after years of testy conversation, Alison conceded on this one -- Greg and Alison now agree, they're different. But how? This two (maybe three?!)-...