Perry Farrell, being the rock sheik that he is, kept wide-eying reminders to grumpy, rained-out folk on Friday about how the sun would dominate the rest of the weekend. But he failed to prepare along the way, kids hopping fences and stretching wristbands in his oversight. Or maybe he’s cool like that. Either way, combined with the hot, humid air you could cut with a butter knife, Saturday was a sweaty, unleashed mess of pop, beginning with the Iggy kind.

Norwegian punktress Ida Maria owned the day’s opening gunshot, splicing love-wretched tales off her debut LP, Fortress Round My Heart, demanding the crowd take off their clothes, she herself leading the movement.  It’s kind of easy when you have songs that promote being naked, though. The 25-year old capped her set with The Stooges sludgy three-chord classic, “I Wanna Be Your Dog,” straddling the stage bare-chest to sultrify the second verse, “And now I’m ready to feel your hand / And lose my heart on the burning sands.”

Aside from a placid 15-minute Band of Horses surprise on the Kidzapalooza Stage, for wee rockers and their parents, with the heaviest moment of rock paired with metaphors about “Nature” for the new season of Nickelodeon’s Yo Gabba Gabba! series, singer/songwriters came ready to entertain the masses. Joe Pug being on the top of that list, amping sounds from his apt weeping willow folk EP, Nation of Heat, with a full band, slide guitar shreds and all, swilling cans of Bud in the spaces.

I can’t tell you if the South Side of the field channeled the same energy, but up on the North, Perry’s DJ pit dueled with heavy-hitters from TV on the Radio to Beastie-Boys-pinch-hitters, the Yeah Yeah Yeahs, creating a triangle of elbow-to-elbow, cattle-like exoduses every half hour, Perry chiming in around 4 p.m. to promote, once again, the enlargement of his namesake stage with a nod to the many “dance enthusiasts in Chicago,” and how his production team had “no idea” how much it’s embraced.

Meanwhile, Santigold, hot off the trails from her European tour, was gearing up to incite a handful of fans to climb on top of the sound booth and damn near collapse the thing during a speedy cover of the Cure’s “Killing an Arab,” that paired with a duo of stoic, synchronized dancers up on stage, was ten-fold the hip-shakery that Perry’s hoped to be that evening.  Even with the many that let the heat get the best of them come nightfall (fallen soldiers below).  But he’s still got Jane’s Addiction to unveil tomorrow.