On Saturday, the opening night of their 'Raising Sand' tour, rock royalty Robert Plant and Americana goddess Alison Krauss turned the brilliant and bizarre musical songbook of their platinum-selling pairing into an evening of chill-bump performances and extraordinary musicianship.

Audience expectation was high from the moment Krauss and Led Zeppelin's front man entered from opposite sides of the Louisville Palace stage and joined hands briefly before settling at separate microphones and launching into 'Rich Woman,' the opening track from their 2007 album.

Though some fans appeared to want more Plant and less Krauss ("Sing 'Stairway to Heaven!'," cried one woman, which prompted a hearty laugh from Plant), others preferred their octane a bit more un-Led-ed. What they got was nearly the full repertoire from the haunting and atmospheric 'Raising Sand,' two songs from producer T-Bone Burnett (who also served as guitarist and bandleader), Krauss' 'Down to the River to Pray' (done a capella quartet style), and a ouhonkin' George Jones encore ('One Woman Man') that seemed to go with Plant's white cowboy boots. But the biggest surprise was the handful of radically folk-configured Zeppelin tunes ('Black Country Woman,' 'The Battle of Evermore' and 'Black Dog'), the last of which, laced with a spooky and spellbinding banjo, brought down the house.

Band members Buddy Miller (guitar, steel guitar), Stuart Duncan (fiddle, mandolin, banjo), Dennis Crouch (bass) and Jay Bellerose (drums) -- the latter two played on the album -- wrestled with a few out-of-tune instruments and microphone problems. But if Plant and Krauss had opening night jitters, they hid them well. Krauss stunned the audience with new power in her trademark feathery vocals, and proved nearly transcendent in her pitch-perfect performances of Sam Phillips' 'Sister Rosetta Goes Before Us' and Tom Waits' 'Trampled Rose,' during which the crowd dared not breathe. Dressed in a peach-pink dress that might have doubled as a prom gown, she dispensed with her usual comedic stage talk and kept nearly mum, letting the leonine-maned Plant make introductory remarks and billboard a few songs (Townes Van Zandt's deeply morose 'Nothin',' which Plant called "shards of words.") While he picked up the mic stand on that song to work the stage -- too small for such an arena-sized move -- it was his only rock star pose. Mostly he stood spread-legged before the mic and concentrated on the pair's precise -- and often Everly Brothers' influenced -- harmonies instead of his Zeppelin-ish howl.

Newcomer Sharon Little opened, her smoky alto selling tortured rock-blues, though it was times hard to believe such angst from a pigtailed blond.

The 'Raising Sand' tour continues into July, with European dates in May.