Keeping up with Sinéad O'Connor's existential contortions is a bit like chasing dandelion fuzz in a hurricane. Her latest album, the covers collection Throw Down Your Arms, is a proclamation of Rastafarianism that at least does her a good musical turn. With everyone from Willie Nelson to My Morning Jacket pillaging reggae for creative inspiration, Arms ranks as one of the more pristine and beautiful excursions in musical tourism. The political stridency, heavy-handed moralism, repetitious uplift, and bare-bones simplicity all provide an almost perfect intersection for O'Connor's personality and her haunting, wounded voice. On Peter Tosh's "Downpressor Man," she infuses judgment-day poetry with church-choir purity and a deep well of anger belied by her surface delicacy. She's never sounded more subtly in control of her pipes, rarely pulling any stunt wails, instead loading her interpretations with fierce density and quiet fire. Jah, man.