On her acidic, intermittently great fifteenth album, Ani DiFranco abandons jam-band buoyancy for pensive, medium-tempo songs and torrents of emo-poetry. She chases insights both cosmic and intimate: “Animal” derides consumers “shopping for the same blank stare,” while “Origami” proclaims that “men are delicate origami creatures; they need women to unfold them when they cry.” Her observations are trenchant, but it’s DiFranco’s glib, slithering delivery that’s transfixing. Each selection comes with its own cast of characters haunting the background — via multi-track, DiFranco supports the pensive ballad “Bodily” with distant voices that alternately shadow the melody and tear it apart. Poetic interludes grow wearisome, and DiFranco has already exhausted many of the themes here, but these are among the most rivetingly unconventional vocal performances she’s ever offered.