It rained all night in Chicago. And all morning. But around 1:30 p.m., when Jay Reatard [ tickets ] took the stage to play a furious half-hour set, the weather finally broke.

However, the thousands of damp fans who packed into Union Park seemed determined to make the best of the damp, dirty day. By 2:30, the sun was out and the immense crowd waiting for the harmonizing Fleet Foxes [ tickets ] began to bake. Wake and bake, actually, as the bedraggled fans once again turned to herbal refreshment to get the day going. One more note about this crowd: if muttonchops were some primitive form of currency, this would have been the richest tribe on the face of the earth.

Brit rapper Dizzee Rascal [ tickets ] was up next, serving as some kind of party-starting, booty-shaking antidote to the Fleet Foxes. And man, that guy tried hard to get the crowd going. He even managed a respectable call-and-response sesh during "Fix Up, Look Sharp," but Dizzee ended up being waiting-around music for the massive crowd waiting for Vampire Weekend [ tickets ] over at the Aluminum Stage.

Vampire Weekend. Vampire Weekend. Vampire Weekend. When you blow up as quickly as these East-Coast smartypantses did, your crowd is going to be a little insufferable. Everyone knew last year's EP and were waiting for either "Oxford Comma" or "Cape Cod" so they could blare along and flair accessories ranging from Gucci bags to bike helmets. When those songs weren't playing, a few fans tried repeatedly (and always in vain) to bribe a security guard so they could go into the photographer's pit to take pictures of Ezra the frontman with their Blackberries.

After the much-anticipated Vampire Weekend set, a lot of the crowd dispersed to tank up on fluids and food for the long evening ahead. P4K's food selection kicks the ass of all other music festivals. Vegan and veg food abounds. Curries rule. Ribs taunt. The beverage selection is a bit trickier. There's water, juice, beer or something called Sparks, which is taurine- and caffeine-infused alchopop the color of deeply concentrated urine. Most go for beer.

On the fashion front, P4K delivers example after example of amazing hipster couture. While most attendees dressed in fairly normal garb (Threadless.com T-shirts, cargo shorts), others decided to look like Dan Deacon clones or circa 1978 Denny's waitresses. Other notable trends include: 1) Cheap, neon-framed sunglasses and Hawaiian print trucker hats so their wearers looked like they came out of a Burger King kids meal; 2) Maxi dresses worn on a wet day, featuring at least a foot of dirt-caked hem; and 3) Short-shorts, which are always a don't unless you are the ghost of an ABA player or a never-nude.

But back to the music! We left off at Vampire Weekend and their dubious fanbase. Contrast the relative newness (and possible fickleness) of these fans with the more stalwart bunch cheering on The Hold Steady [ tickets ] and especially those who went wild for ex-Pulp frontman Jarvis Cocker [ tickets ]. What a snake-hipped wonder he is. Surely there was no performer today more charismatic, witty or entertaining than Mr.Cocker. He, like many of the artists this weekend, emphatically endorsed the candidacy of Illinois Senator Barack Obama. And right after he did this, he played "Cunts Still Run The World."

Closing today was Animal Collective [ tickets ]. It seemed to take the band a while to settle into their set, but the crowd was too hypnotized by the Simon-like multicolored light show to try to make a break for the train just yet. Patience was rewarded with volume and bass.

Tomorrow still stretches long before P4K attendees. Will HEALTH make everyone go insane early in the afternoon? Will Zooey Deschanel make a guest appearance during M. Ward's set? Will Spoon, for a change, not suck live?

Read Friday's Pitchfork fest report