New is the order of the day, and that new can range from the startling to the inconsequential. The Kronos does not guarantee profundity. It just likes to keep the conversation going. Concerts at Zankel Hall on Friday and Saturday (a third called "Notes From Azerbaijan" was yesterday) drew the kinds of listeners the quartet has cultivated over the years � people who like their art with social consciousness, ethnic relevance and a few surprises. Twelve-toners and intellectual provocateurs beware: this is not the music for you.