Get ready for a very dramatic, incredibly extra set of songs (and only some of them have the excuse of being written for the stage.) Artists like Scott Walker and Richard Harris lean into that ripe, campy quality with bizarre lyrics about gold-toothed barmaids and melting cakes. Others, though, play it deadly real. “Cabaret” is both flamboyantly huge and truly devastating, and “Being Alive” plays like a real epiphany, as if the distancing conceit of the theater has dropped away entirely.