It's tough to launch a festival after work on a Friday (7/18), but the crowds braved late-afternoon heat, a sudden downpour and ridiculous public-transit waits for the Pitchfork Music Festival [ tickets ], or as it is known by the kids in the know, P4K.

Today was mostly a big deal if you were into Mission of Burma [ tickets ], Sebadoh [ tickets ] or Public Enemy [ tickets ]. And the crowd was mostly into Public Enemy. And beer. And marijuana.

First up, Mission of Burma, playing 1982's "Vs." So it was totally appropriate that the hard-core core of the middling-sized crowd was mostly folks in their late 30s/early 40s. All over the Midwest, mid-level professionals took one solitary vacation day to set up folding chairs, bob their heads and have a couple of beers while watching their aging rock heroes do it up right. But as soon as MoB endorsed Barack Obama and played their last note at 7:30 p.m., at least half the crowd went to go wait in front of the Aluminum Stage for the 8:30 PE show.

Today was the perfect day to shop at the Flatstock Poster Fair and DEPART-ment indie boutique before grubby hipsters and their grubby hipster paws left fingerprints on that one Thomas Dolby record you've been looking for. Apparently, Lucite jewelry is gonna be huge this year.

Back at Sebadoh! The band cranked away at "Bubble and Scrape" from 1993, much to the delight of their mid-30s fan base. Somewhere during the middle of the set, after a second beer, the crowd seemed to finally realize that they were at a rock show. People settled into jerky, punk-rock dances perfected a dozen-plus years ago in smoky, grotty hometown clubs. And ever so subtly, the smell of pot wafted over the crowd, and you could feel all of Union Park relax.

Over at the Aluminum stage, which had been quickly filling up since MoB finished, PE producers the Bomb Squad were testing out their speakers and decks. And 15 minutes before Sebadoh's set ended, Bomb Squad started up, then realized their faux pas and quit. But it didn't matter because the entire audience was cramming into the Aluminum area. Bomb Squad started up in earnest and the low-frequency bass signaled to the crowd that they should begin smoking immense quantities of weed.

Public Enemy! You are the great unifier of all people! PE's performance of "It Takes a Nation of Millions to Hold Us Back" united the crowd in a way that MoB or Sebadoh were totally ill-suited to do. After "Bring the Noise," Chuck D's mic problems were fixed and Flavor Flav was located. That beclocked little reality-TV clown is, without a doubt, totally ridiculous, but the man can entertain, fending off the boos from "Flavor of Love" haters with, "Call your spouse 'boo,' not your boy Flavor Flav!" And whether it was all of the secondhand weed smoke, the anticipation of two more days of awesome music or entirely Public Enemy, everyone--everyone--started dancing.

Up tomorrow: The tragic fashion at P4K. Why do hipster girls rock thick knit tights with rubber galoshes on 90-degree days? Plus !!!, Vampire Weekend, Dizzee Rascal and more.

Read Saturday's Pitchfork fest report