Variety's Abe Burns reports from the front lines at this weekend's Lollapalooza festival in downtown Chicago.

The Octopus Project was one of the first bands heard on the final day of Lollapaloza. The crowd trickled in and it was already more hot and humid than before. Sunday felt slower, with not as many bands scheduled at the same time and the crowd was just tame.

Chicago's own Kid Sister brought the energy level up, sampling the Beastie Boys classic "Intergalactic" and dancing onstage in a yellow, blue and pink getup. Walking through the open field all you could hear was a low bass rumble and Melissa Young singing 'Hit me on my beepa, beepa, beepa". In sharp contrast The Whigs gave a more fitting soundtrack to the intense heat of Sunday afternoon – their distorted guitars, bombastic drums and vintage organ attracted a sizeable crowd. They received a huge response, mostly from fans who were still filtering in from the front entrance. The Southern three-piece broadcast from the MySpace stage, across the field that had been battered by a raucous show the night before (Rage Against the Machine). Hungover, tired and overheated, the people still came, intrigued. The Whigs launched into "Mission Control", which echoed out and became soothing when combined with the muggy air.

Brazilian Girls felt the same way -- "Don't Stop" and audience favorite "Pussy" were enough to placate the crowd in such uncomfortable humidity. Getting away from the intense conditions there was much to explore in and out of the park walls. At the Hard Rock Hotel (only a couple blocks away) Trent Reznor-produced Saul Williams (who distributed his latest album on his website for free) roamed the 4th floor, taken over by Diesel.

Then on to Mark Ronson (left), with all hands in the air. Ronson opened up all the stops -- a string quartet, 3 backup singers and a 4 piece band (not including Ronson, who stuck to his guitar). There were guest singers galore: Kenna, Candie Payne and Daniel Merriweather who performed The White Stripes' "You Don't Know What Love Is (You Just Do As Your Told)." A highlight came when Alex Greenwald joined Ronson onstage for a rendition of Radiohead's "Just," followed by Phantom Planet playing "California."

(Photos by Brecheisen, WireImage)