At first thought, Robert Plant might seem an unlikely outlet for a celebration of Americana. But think about the myriad sounds from the colonies that Led Zeppelin melded into its music, and it makes sense.

According to Reuters, aftr a long collaboration with bluegrass torchbearer Alison Krauss has produced a platinum album, a Grammy and now a tour that melds a litany of American roots influences into a tasty gumbo.

Plant and Krauss traded off and shared often understated vocals as the band culled sounds both esoteric and familiar. Leading with the record's reverb-drenched, midtempo opener "Rich Woman," the two-hour show skipped across genres with a reverent exuberance.

The crowd, of course, wildly cheered early on when the band sneaked into Zeppelin. But this was a much different "Black Dog" -- a slow, growling, barely leashed blues. Plant's original wail was muzzled into a soft-spoken duet with Krauss that later featured a fiddle solo -- about as far away from Zep land as it could be.