The Acoustic Café Tour is smartly arranged as a study in post-Lilith Fair, singer-songwriter contrasts. Veteran songwriter Mary Gauthier sings with a cutting drawl and writes brutal fables that merit comparisons to both Flannery O'Connor and Townes Van Zandt. Carrie Rodriguez also knows how to hold an audience with a sculpted lyric, but her method is a sweeter science, part fiddle brilliance, part Texas soul. The youngest of the three, Erin McKeown, brings some levity and pop impulses to the bill and should be a draw for fans of Ani DiFranco's satirical groove folk. If you're looking for a night of dainty songbirds in polished folkie cages, disappointment is certain — this trio has sharper, shrewder songs to share.