Filling every level of the Fillmore Theatre, against the blue-lit chandeliers and gilded moldings, the crowd gathered for Regina Spektor on this blustery Wednesday night is anything but ordinary: a gang of 30-something Russians mumble small talk with a contingent of elderly bald men, a few track-jacket scenesters sip drinks with suits at the center bar, and a 40-year-old mother of two talks with awestruck tween-poppers. All eyes are fixated on three warm track lights hanging quietly over a worn black piano