People in more polyester than usual seemed to be conversing from some Talking Points Memo on Brecht and Weill. Is this opera? Should it be amplified? Is it politically relevant? Is it Broadway? With the placards displayed as a scrolling, electronic billboard, the political sentiments are just as spot on as they were more than a half a century ago. The orchestral attack and the chorus' precision matched any traditional opera. The narrative and forced participation of the audience in the final act definitely separates it from the Broadway fare it is alleged to have inspired (''Cabaret,'' ''Chicago,'' et al.). Go see ''Grey Gardens'' or ''Wicked'' next time.