Watch a slideshow of Neko Case at Bumbershoot. Photo by Renee McMahonNeko CaseWhere: Samsung Mainstage, When: Saturday, Aug. 30, 1 p.m. Neko Case hasn’t put out anything new since Fox Confessor Brings the Flood, but the impatient got a sneak peek at a few songs from Neko Case’s next record, which is slated to come out in March. Though the set list leaned toward the soulful ballad, Neko sang with the same soulful concentratrion of all her live performances, belting out challenging numbers like “Star Witness” and “John the Baptist” with her face turned upward in defiance of all my childhood choir teachers’ best advice. If only she’d humor those of us who dug her bluegrassier days and sing “Guided By Wire,” or “Hex” once in a while…not that I’m complaining, because of all the times I’ve seen Neko sing live, she’s never been anything less than astounding.