Joe Leydon Film Critic How far will you go to deny your identity in order to be a somebody? What happens when you make a deal with a devil whom you might normally despise, but has transfixed much of an entire nation’s population? And how long can you will yourself to ignore evidence of the intolerable? These are just a few of the questions raised — sometimes with allusive finesse, sometimes with blunt-force impact — during “The Performance,” an enthralling period drama with often disquieting contemporary relevance. If you have roamed through this cinematic territory before, you may discern in Shira Piven’s exceptional film traces of “Cabaret,” “Mephisto” and other tales of ambitious entertainers striving for the spotlight as Adolf Hitler’s shadow spreads over 1930s Germany.