As summer approaches, live music fans have plenty of outdoor options to warm up for the coming festival season. Gov't Mule, Yonder Mountain String Band and Xavier Rudd offered up one more in the cushy confines of Norfolk, VA's Norva, however, and if this year's annual musical gatherings can match this six-hour indoor blowout, it may take a heavy winter to cool off the campgrounds of America.

Opener Xavier Rudd’s aboriginal blues stomped through the Norva like ritualistic bodies around the fire, warming the crowd with heavy organic grooves and spirited vocals. Opening with "Conceal Me," Rudd moved through the breadth of his catalog, injecting melodies into the thudding rattle and buzz of acoustic guitar and didgeridoo before opening up to let his guitar scream and sing over stomp-box beats. The deep, southern slide of "Lila" broke open into a quiet, pensive space where Rudd’s mournful voice could explore until a bouncing, locomotive rhythm and wailing harmonica got the crowd’s knees jerking and feet moving. On "To Let," Rudd showed just how much noise one man can make with a few quiet, campfire instruments, sending sparks flying as he threw a monstrous log onto the song’s soft, glowing interlude and exploded into a huge, towering inferno to close his set.

Colorado’s Yonder Mountain String Band let its fire burn more slow and steady but occasionally kicked up a few of their own sparks with their Rocky Mountain breed of Appalachia. Mandolinist Jeff Austin did most of the talking through the first few numbers, both verbally and musically. His solo on "Steep Grade, Sharp Curves" finished with a flourish before leaving an open space for Adam Aijala’s sweet vocals on the Yonder Mountain chestnut, "Left Me in a Hole," and Dave Johnston worked both the crowd and his banjo into a frenzy on the more frenetic "Too Late Now." While "Deep Pockets" swung, "Mental Breakdown" smoked, and the band’s showcase of Jim Lauderdale’s "Red Bird" showed off both the band’s instrumental chops and near-perfect vocal harmonies. Todd Snider’s "Sideshow Blues" proved that where there’s smoke, there’s fire, as Warren Haynes came out for the last two numbers, quietly smoldering on Dylan’s "It Takes a Lot to Laugh, It Takes a Train to Cry," but adding some beautiful slide work to a faithful singalong of the Beatles’ "Dear Prudence."

The crunchy metal blues riffs on the Mule opener, "Mister Man," hinted that Haynes saved the real heat for his own band’s set, though, and the cutting, trick-step riffing on "Lola Leave Your Light On" proved that all eyes were on the man with the guitar. Haynes’s solo howled through the plodding, Godzilla thump of "Mother Earth," which bubbled and gurgled before busting out of the sleeping volcano and dripping over the sides with a thick, glowing heat.

Since taking over for the dearly departed Allen Woody, Mule bassist Andy Hess has slowly found his space in the band, and "Rocking Horse," comforted long-time fans pining for the old days before the band slowed things down on "Fool’s Moon" and "Slow Happy Boys." Matt Abts is clearly the foundation to Mule’s psychedelic blues stomp, and his rumbling rhythm provided the undercurrent for the unrelenting tension of "Trane," which blew by brief glimpses of the Soul Brothers Six classic, "Some Kind of Wonderful" and the Mule original, "Mule." "Beautifully Broken" followed, and glancing down at the time after watching the band walk off the stage after the closing "30 Days in the Hole> I Don’t Need No Dr.> 30 Days in the Hole," it was hard to believe another set was still coming.

After Rudd’s surprise cameo during the break, Gov’t Mule reappeared for a more subdued second set of slower ballads like the Dead-esque opener, "Wine & Blood," the Mule classic "Soulshine" and the Beatles’ "I’m So Tired," which sandwiched a hefty drum solo from Abts. "Thelonius Beck" tripped up the set’s straight ahead chords and blues riffs, and "Slackjaw Jezebel" delivered a needed shot of energy, but it was the closing duo of "Effigy" (with visit to "Folsom Prison Blues") and "Goin’ Out West" (Haynes singing like the song was written for him) that brought the stage back to life before leaving the audience to finish the closing cadence.

The rootsy, Chicago blues of "I Can’t Hold Out" was a fitting finish to an evening so tangled up in roots that it was often hard to tell where one band’s foundations began and the next’s ended. While each came at the audience from a different time and place, they all delivered sincere, empowered music, and their collective authenticity bound the evening together. The bands’ managements couldn’t have planned it better: certainly no one made any enemies, and despite the diversity on the bill, the three bands coalesced into a trinity that, while not divine, was at least inspiring to those standing in front of the stage, as well as on it.