At first glance, this collaboration seems about as likely as pairing Ozzy Osbourne with Norah Jones or matching Steven Tyler with Diana Krall. The idea of classic rock icon Plant recording with fiddle-totin’ bluegrass queen Krall evokes the mental image of a musical train wreck.

But Plant, unlike many hard rock singers of the ’70s, has always been in touch with his acoustic side. While notable for a heavy sound, Plant and his Led Zep mates also tossed in acoustic gems including “That’s The Way,” “Going To California” and “The Battle of Evermore.” By that same measure, Krauss has stretched the bounds of bluegrass by covering numerous pop songs throughout her career. The ability of these two artists to meet in the stylistic middle makes Raising Sand a success. Clearly, Plant is closer to Krauss’s turf here – she is not attempting to scream over a wall of Les Pauls and crashing drums. Produced by T-Bone Burnett, Raising Sand’s 13 tracks finds the two interpreting lesser-known – but well-chosen – material by Tom Waits, Townes Van Zandt, Mel Tillis and The Everly Brothers among others. But the disc’s highlight is the forgotten Gene Clark track “Through The Morning, Through The Night,” a song tailor-made for Krauss’s warm vocals.

Ultimately, Raising Sand is an important reminder that the best music is devoid of labels and transcends genres. After all, if David Bowie and Bing Crosby can record a definitive version of “The Little Drummer Boy,” it shouldn’t be a stretch that Plant and Krauss can find common ground as well. www.rounder.com