Phil Lesh & Friends and the Allman Brothers at Merriweather Post Pavilion

“I don’t even like jam bands,” the engineer told me at Will Call. “I just come to these things to get high.”

I nodded at the child strapped to his back. “You folks are in good company, then. The Beautiful People are out in full force tonight.”

“That’s what they tell me.” The child had begun pawing at the man’s baseball cap. “Say, I’ve been wondering: is it true that Pamela Anderson gave hep C to Phil?”

“Sounds like a dirty rumor.”

“I can believe it,” he shrugged. “They both live in Cali….”

I encountered Mr. Unassailable Logic an hour later at the stage-left lawn entrance, where he was shaking down the tie-dye crowd for coke.

“Come on, you guys gotta hook me up,” he told successive barefoot gaggles. “Hey—yayo? Yip? Anybody?”

“You gotta quit that stuff, man,” ventured a well-wisher.

“Hell, I’m not even looking to party—but I gotta drive back to Pennsylvania tonight and I’ve got work tomorrow. I just wanna travel safe, you know?”

Well shucks, Mr. Logic, I can’t say that I do. But then again, I only came for the music.

The bands, of course, did not disappoint. (At these events, most people know exactly what they’re paying for…and if somehow they don’t get it, the fault is not in the stars.) Phil Lesh & Friends played a marvelous set of Grateful Dead gems, standouts including expansive takes of “Eyes of the World” and “Cassidy” and a jabbingly glorious “The Other One.” Larry Campbell, the greatest contemporary sideman-for-hire not currently playing for the Allmans, led a phenomenal guitar attack, paying deference to Garcia while sharpening the blues licks—his interplay with Barry Sless on pedal steel was a definite highlight, as were the rhythmic contributions of Jackie Greene. Greene’s fluency as lead singer was also a treat, especially for those of us who worried Phil’s voice wouldn’t be up to snuff (it was, though not on par with the tyke’s). “Sugaree,” the encore, was Greene’s finest vocal moment: bluesy, exalted, dead-on.

The concert also offered a glimpse of one particular tangle in the genealogy of jam—a tangle named Warren Haynes. Campbell is a third-generation stand-in for Haynes, who performed frequently with Lesh after an estimable stint as lead guitarist for the Dead (a Jerry-less regrouping of the surviving original members), and whose own band, Gov’t Mule, is an offshoot of the 90s Allman revival.

Revival—duh—is the name of the game at these concerts, and if Lesh & co. channeled Jerry, the Allmans played hot enough to wake the dead (or, you know, the garrulous wrinkled couple dancing next to you). Haynes and Derek (nephew of Butch) Trucks light up this band—if there’s a better two-guitar front on the planet these days, I haven’t heard ‘em. Trucks, a slide mastermind, can elicit drunken moans, angelic sighs, and metallic thunder from his Gibson, all with a nearly passive equanimity. Absentminded, like a man tying his shoes.

Haynes, meanwhile, manages to balance dizzying above-the-fretboard slidework with a bellowing presence at the microphone. On “The Weight”—which resurrects the Aretha/Duane collaboration as much as it does The Band’s original—Haynes proves himself one of our finest white soul singers. And his manipulation of the wah pedal during a “Dazed & Confused” digression (placed immaculately before the dénouement of “Mountain Jam”) constitutes a three-minute aria.

And then there’s Gregg Allman, whose voice has only gotten better in the last ten years (cf. Monday’s rendition of “Dreams”), and who now looks something like St. Nicholas.

The encore, “One Way Out,” kept the crowd shrieking for more and rendered powerless the hitherto draconian Merriweather dance police. The Allmans weren’t losing steam and probably could have played all night. But why push their luck? The band’s already on its third wind.