CHICAGO — An earlier generation looked to Frank Sinatra — even an over-the-hill, Sinead O’Connor-bashing, Frank Sinatra — as its graying icon of cultural hip. At last weekend’s Pitchfork Music Festival, staged at Union Park in Chicago, the influence of 30 years of punk rock and hiphop marked a changing of the guard.

Here was Sonic Youth, artfully reconstructing its landmark album “Daydream Nation” not exactly note-for-note, for an audience that was probably in diapers when the record was released in 1988. It was the same audience, about 18,000 strong and overwhelmingly white, that threw its “Wu Hands” in the air during a playful and free-flowing set by the GZA — resident “genius” of rap’s pathbreaking Wu-Tang Clan — who reprised his 1995 classic, “Liquid Swords.”

The three-day festival, organized by the Chicago-based music Web site Pitchfork Media (www.pitchforkmedia.com), flaunts a curatorial bent that sets it slightly apart from the season’s other big pop fests, which these days are mostly consigned to a single location. The only touring festivals still active, such as Ozzfest and Warped, coalesce around notions of genre — like commercial heavy metal — with ferocious fan bases. The more diffuse agenda of festivals such as Lollapalooza (which hits Chicago August 3-5), Southern California’s Coachella, and Tennessee’s Bonnaroo, makes them more and more interchangeable as far as lineups go. If an Ozzfest favorite like the heavyrock act Tool can headline at the jam band and songwriter-driven Bonnaroo, then anything goes. These outdoor parties begin to function much as European music festivals do — like giant popmarts that use geographic backdrops or a vague aesthetic to distinguish themselves where little else does.

Pitchfork is different in that the bookings are an extension of the Web site’s critical tastes. And those tastes are rigorously eclectic. While headliners included some predictable indie-rock darlings — Cat Power and the New Pornographers — the stages also boasted strong dance/DJ acts such as Jamie Lidell and Dan Deacon, and buzzy outfits like Deerhunter, whose reputation Pitchfork has done much to foster.

The philosophy includes the corporate presence at the event (Fuze and Chipotle, not Pepsi and Burger King), as well as a sprawling record emporium, local vendor booths, and a major rock poster market called Flatstock, where visitors could find 20 different inspired graphic salutes to the Decemberists and Modest Mouse.

Founded in 1995 by a Minneapolis teenager named Ryan Schreiber, pitchforkmedia.com has mushroomed into a widely influential Web presence that gets about 200,000 hits a day. When promoter Jeff Hunt, who staged a five-day festival in Atlanta last year to celebrate his avant-garde Table of the Elements label, got a front-page review of the event in Pitchfork, he was ecstatic. “It’s like being on the cover of Rolling Stone in the late 1960s,” he said. The immediacy of the Internet, and the fanzine enthusiasm of Pitchfork’s writers — who rarely espouse a middling opinion — makes the print versions of Jann Wenner’s rock Bible and its snarkier rival, Blender, appear slow on the draw, if more slickly professional.

That’s especially true when it comes to breaking bands in a business that is increasingly focused away from major-label influence. Battles, a New York-based quartet that creates intricate, pulsating abstractions with guitars, keyboards, loops, and crisp, hammering drums, played Saturday afternoon to a roaring crowd. Earlier this year, the group’s debut album, “Mirrored” (Warp), got a coveted 9.1 (out of 10) rating from Pitchfork.

“To keep us on their radar is cool,” Tyondai Braxton, one of the band’s three guitarists, said. Drummer John Stanier (whose “pistons pump out a steroidal version of [Marc] Bolan’s trademark shuff ling stomp-beat,” Pitchfork commented), who once played with the 1990s buzz band Helmet, elaborated on why that matters.

“Pitchfork is way more important,” he said. “It’s the industry standard. A Web site! Who knew it would come to this? It’s 100% completely different now. It’s a different ballgame.”

Mr. Schreiber, who earlier this year moved from Pitchfork’s Chicago base to Brooklyn, downplays the site’s status as an arbiter of indie cool. “We have never gone out of our way to take credit for anything,” Mr. Schreiber, whose moustache and shaggy hair make him look like the indie-rock Bruno Kirby, said. “We just have a really strong relationship with our readers. They like that we’re really honest and we don’t pull any punches.”

The site receives frequent jabs, however, as detractors criticize the obsessively analytical slant of certain reviews and the collegiate flailing toward literary effect. The snarky Web site Idolator.com(part of the Gawker Media chain) runs a feature called “The Pick of the Fork” in which it digs up the “gonzoest of the gonzo writing” on the site. A June 14 entry complains: “We were slightly dumbfounded by this weirdly out-ofwhack 4.4 review of Pelican’s ‘City Of Echoes,’ which is essentially an 800-word referendum on how much the drummer allegedly sucks, and how said suckiness bungled what is otherwise ‘the best Pelican album yet.’ What?”

Such carping is, of course, record geekdom at its finest. And, for all its generation-next street credit, Pitchfork is a celebration of old-fashioned record geekdom. The concept of having bands play their classic albums front-to-back was popularized several years ago by England’s All Tomorrow’s Parties festival, which has a series called Don’t Look Back devoted to such events. Sonic Youth is taking the concept on the road, with a July 28 performance of “Daydream Nation” at McCarren Park Pool in Greenpoint, Brooklyn.

The canonical approach may be a sneaky way for aging Generation X’ers and Y’ers to have their nostalgia and still feel superior to their peers, who are spending the summer flocking to hear 1980s hair-metal reunion tours or spandex pop on the summer shed circuit. Even if it all feels a bit “High Fidelity,” with Nick Hornby’s vinyl junkies arguing over their Top 5 lists, it’s a validation of astute fan-hood. Promoting that idea makes Pitchfork look sharp, indeed.