Like any music, jazz has its revolutions; its sudden incidents in infrastructure; its disruptive presences of unprecedented sound. Mostly it's slower than that, though, with years and generations of accretions before it seems to call for new vocabulary. That's one way to look at Winter Rockfest, whose latest incarnation occupied a dozen or so venues in downtown New York City last weekend. In a decade and a half of steady growth, a one-night showcase oriented toward industry insiders has become […]