Led Zeppelin frontman Robert Plant and bluegrass crooner Alison Krauss may not be the likeliest of musical combinations. But on this welcome collaboration album, they work beautifully together, wringing a kind of magic from other peoples songs. The key to the album is its versatility. Between them, Krauss and Plant can handle a vast repertoire on their own, and here they take on the lot, from folk laments and country soul to searing blues and upbeat rock & roll. Overseen by Elvis Costello producer T Bone Burnett and backed by high caliber musicians like guitarist Marc Ribot and multi-instrumentalist Mike Seeger, Raising Sand sees the duo create stellar covers of songs by Tom Waits, Townes Van Zandt, Mel Tillis and The Everly Brothers, among others. Highlights include a killer version of Roly Salley's "Killing the Blues", and a cover of the Plant-Page collaboration "Please Read the Letter," though in truth, its difficult to find a weak spot on the whole album.