If the second day of Mountain Jam was all about showing deference to classic rock forefathers, day three (June 6) was about confronting those influences, and pushing blues and Americana in new directions.

Since the Black Keys arrived more than 10 years ago, they've presented a challenge to the classic rock-informed status quo, with a deceptive simplicity and spindly riffs that draw more from outsiders like Junior Kimbrough than arena stars like Jimmy Page. In their headlining set at Mountain Jam last night, simplicity -- in both stage and sound -- served as the unobtrusive platform for Dan Auerbach's singing and playing, on radio hits like "Gold on the Ceiling" and "Lonely Boy."

As day two headliners, the Keys were the big draw. Bethany Gessinger and Fahad Syed drove down from Fonda, N.Y. -- near Albany -- and spilled out on lawn chairs early in the day, still basking in Robert Plant's performance from Friday night. "It was epic," said Syed, who was wearing a black top hat. "With the wind coming up -- it was beautiful."

Rob Douglas, sitting with his wife on a blanket, was biting open a bag of beef jerky. Rob was bummed he missed Plant -- they rolled in at 4 AM Saturday morning -- but, like Syed, couldn't wait to see the Black Keys, as well as Rusted Root. Douglas stopped us as we were about to walk away. "I hope the promoters keep it going," he said, gesturing toward the stage. "Since the Dead is gone now, it just doesn't happen as much."

No one at the festival held the audience as closely as Shakey Graves, who plays a blues stomp, with loud kick drum beats and snaking, sinister riffs that together recall dance music as much as blues. If the prior day’s performances from Grace Potter and Trigger Hippy were homages to classic forms, Shakey’s show felt bold and immediate, especially if the dudes standing right up to the stage waving their arms were any indication.

And that was after Benjamin Booker took the stage cursing pop music and 40-year-old producers. Unlike Potter, who clearly carries the torch from legends like Janis Joplin and Mahalia Jackson, Booker sings the blues like no one — instead of listening to an old Otis Redding record for inspiration, he just up and swallowed it, and spit it out over noisy, joyful guitar.

Also taking the stage Saturday were Gov't Mule, delivering a more-straightforward set to complement their Pink Floyd tribute from Friday night, alongside Rusted Root and their Dead-tinged folk and world music rhythms. The funk jam band Dopapod, the first main stage act of the day, told the crowd they used to sneak in and play impromptu gigs in the campground.

Day four of Mountain Jam features headliners the Alabama Shakes, with supporting performances from Hurray for the Riff Raff and Michael Franti and Spearhead, among others.