Sheer artistry might be the best way to describe Tracy Chapman's stunning performance at the nearly sold-out Orpheum on Tuesday. She transfixed her fans with fiery political anthems, killed them softly with the most hushed love songs imaginable, and won them over with a varied repertoire that has only deepened since she was a student at Tufts in the late 1980s.
Chapman was magnificent from start to finish. She was shy and retiring in her stage banter (''As some of you know, I used to live here," she said sheepishly), but she was overwhelmingly powerful when she began singing. Fronting a trio that ably followed her every nuance, she captured the crowd instantly with two working-class anthems, ''Subcity" (about being left behind by the American Dream) and the urgent ''Why?"