Alison Krauss and Robert Plant at the Greek Theatre, 6/23/08The stifling heatwave that gripped southern California for a full week blew away just in time for Robert Plant and Alison Krauss to fill L.A.’s Greek Theatre with music and people for two nights early this week. Unfortunately, while the music was quite wonderful, many of the concertgoers at Monday’s gig seemed kinda miffed – or at least nonplussed.

“I’m bored already,” a fiftysomething woman told my wife not four songs into the main attraction. Afterward, a man I’d never seen before sidled up to me and said, “I thought Plant was gonna play more of the old stuff. Didn’t you? I’d heard he was gonna do a solo set at some point.”

Apparently not. In fact, from a quick scouring of Plant-obsessive websites, it appears that Monday’s set was identical to the ones this new dynamic duo have been playing throughout their tour behind the magnificent Raising Sand album. Still, I’d guess that more than half the 5,800 souls who filled the Greek arrived expecting Robert Plant to be, you know, Robert Plant.

On those few occasions when Plant allowed a smidge of the old Zeppelin pomp to sneak into his voice or demeanor, a Pavlovian standing ovation would erupt. Most of the time, however, Plant remained a cool customer, reveling in the Southern-goth rockabilly-bluegrass concoction that he, Krauss, and producer/sideman T Bone Burnett have cooked up for this album and tour. And the plurality of patrons who had driven into L.A.’s Griffith Park expecting an evening of Cock Rock didn’t know what to do with themselves.

It’s a shame, really, because in their ambivalence they may not have noticed what a remarkable show the “Raising Sand revue,” as Plant has labeled it, truly is. Using the album’s riveting blend of R&B, early-rock and gospel covers as a springboard, Plant, Krauss and Burnett retrofitted classics from the Zep catalog (“Black Dog,” “The Battle of Evermore”) as well as a Ray Charles chestnut (“Leave My Woman Alone”) and a couple old-timey hymns. During one centerpiece of the set, Krauss’ always-virtuosic fiddle easily replaced the synths that once washed over Plant’s solo hit “In the Mood”; in mid-song she briefly banished contemporary music altogether to indulge in a couple verses of the 17th-century Child ballad “Mattie Groves.”

Plant clearly is enjoying the Raising Sand project, which Burnett nurtured from an unlikely vocal pairing into a match made in heaven. On Monday, Plant and Krauss entered from opposite sides of the stage, but their voices quickly blended beautifully in the chilly L.A. night as they launched into the ’50s swamp-rocker “Rich Woman.” The sound of Raising Sand is the sound of both vocalists slipping out of their comfort zones just enough to meld with each other, and with Burnett’s dark, intricate arrangements. Thus, Krauss’ plaintive yet soaring fills offered a sometimes soothing, sometimes unnerving counterpoint to Plant’s earthy growls on songs like Rollie Salley’s “Killing the Blues,” Mel Tillis’ “Stick With Me Baby,” and “Please Read the Letter,” a song Plant co-wrote with Jimmy Page for the duo’s Walking into Clarksdale album.

Even when Plant claimed center stage for himself on Zep’s “Black Country Woman,” Allen Toussaint’s “Fortune Teller” and Townes van Zandt’s “Nothin’,” he stayed largely in the pocket; his performance – and his demeanor – reflected not a rock god indulging in a genre exercise, but an aficionado of American music basking in a style he’s always wanted to sing.

T Bone BurnettThroughout, the principals were boosted by the extraordinary work of what must be one of the greatest pickup bands ever assembled. On one guitar was Burnett, whose genius as an arranger of songs and people is matched by his technical prowess in playing the style of retro-contemporary rockabilly he has godfathered and championed. On the other was country-folk virtuoso Buddy Miller, whose roaring solos put teeth into the tunes (and occasionally inspired moments of old-style swagger from Plant). Drummer Jay Bellerose appears unobtrusive (when was the last time the drummer was the only guy onstage wearing a necktie?), but he performed swirling wonders on “Fortune Teller” and helped Plant turn van Zandt’s “Nothin’” into, ironically, the evening’s most Zeppelinesque moment. Utility man Stuart Duncan raged on banjo, guitar and mandolin; as a fiery solo worthy of Jimmy Page ripped through the bridge of “Black Dog,” I looked first to Miller and then to Burnett before realizing that the blistering sound was coming from Duncan…on a fiddle.

Still, the key ingredient in this polyglot musical stew, as any of the male participants will surely attest, is Krauss. Quite simply, she once again confirmed her status as the reigning MVP of Americana music. Stepping out of the comfortable confines of her bluegrass band Union Station for the first time on a major tour, she showcased all the talents that must make her the busiest artist in the music industry.

Alison KraussHer fiddle work was magical all night, and her skills as a backing vocalist ratcheted up the intensity on “Fortune Teller” and Johnny Horton’s “One Woman Man.” More important, Krauss dominated long stretches of the show with a stunning range of lead-vocal performances. Her take on Sam Phillips’ chamber-pop number “Sister Rosetta Goes Before Us” is the loveliest thing on Raising Sand, and she matched it with the Union Station-ish “Through the Morning, Through the Night” and a mini-set of gospel numbers that concluded with Plant, Duncan and Miller joining her for an a cappella “Down to the River and Pray” (from the O Brother, Where Art Thou? Soundtrack). Her greatest glory, however, came on Tom Waits’ “Trampled Rose”; her pitch-perfect, octave-scaling moans created the evening’s most haunting moment.

As Plant and Krauss launched into the set’s climactic rocker, the Everly Brothers rave-up “Gone Gone Gone (Done Moved On)” that has become Raising Sand‘s calling card, a perplexed woman in front of me finally turned around and asked, “Do you know where she came from?” I responded, “Do you mean, ‘Where did she grow up?’ or ‘Where has she been all your life?’” The woman stared at me blankly, so I chose the easy way out: “Kentucky, I think.” (Wrong! Krauss actually grew up in Champaign, IL. So sue me.)

Her muted response was, sadly, all too typical among the thousands who apparently didn’t get what they came for Monday night. Sure, the encore included a rousing (but distinctly non-Zeppelinish) version of “When the Levee Breaks,” but Plant and Krauss stayed true to their album’s vision to the end, closing with an exquisite duet on Doc Watson’s ballad “Your Long Journey.” Then they sent their audience out into the night with Plant’s jaunty “We’ll be back – see you next time.” Hopefully, next time the crowd will have a better appreciation for what they’re listening to.