Perhaps only the fantasy duo of King Kong and Bambi could be a more bizarre pairing than Robert Plant and Alison Krauss. Yet on Raising Sand, their haunting and brilliant collaboration, the Led Zeppelin screamer and Nashville's most hypnotic song whisperer seem made for each other. This, however, is not the howling Plant of "Whole Lotta Love," but a far more precise and softer singer than even the one who emerged with Dreamland (2002).