At best, Winter Jazzfest is an extraordinary thing. It’s a significant jazz festival, not tied to any cultural institution. And it doesn’t rely on the names that would fill Carnegie Hall or Rose Theater, but on those that make up the music’s daily life, chosen with discernment and advocacy. That’s inspired. It took the form of about 60 performances (I passed through about a third of them) spread across Friday and Saturday in five rooms on or near Bleecker Street: Le Poisson Rouge, Sullivan Hall, Kenny’s Castaways, Zinc Bar, the Bitter End. Since 2005 Winter Jazzfest has leaned toward new groups, playing new music, and it helps push them into visibility: different audiences — twice as big or more as those groups would usually draw — enacting a different kind of listening, a sorting-out and contextualizing kind.