Pitchfork Music Festival gets underway (photo by Kate Gardiner/NewsHour)

Officially getting underway in the West Side’s Union Park amid 90-degree temperatures and under a bright blazing sun at 3:30 Friday afternoon, the Pitchfork Music Festival was slower to kick into gear in terms of musical excitement today than it was during any of the five preceding years (or six, if we count its origins as the Intonation Festival in 2005).

Pitchfork 2010 abandoned the “Don’t Look Back” concept of revered indie-rock heroes holding forth on opening day by playing one of their classic albums in its entirety, which was not necessarily a bad thing, given the mixed results of recent years (Slint and GZA, a let-down; Mission of Burma and Public Enemy, pretty darn great) and the taint of nostalgia that always lingered over that endeavor.

Unfortunately, in starting a few hours earlier, promoters seemed to assume that the crowd would be slow in arriving–it wasn’t; the fields in front of the main stages were respectably full from the moment the gates swung open—and that things would be pretty sleepy early on. At least, that’s the only logic I can think of for starting with two sets by snoozy performers playing solo acoustic.

Born in New Jersey, raised in Tennessee, and now based in Brooklyn, singer-songwriter Sharon Van Etten was here on the strength of her perfectly pleasant but far from unremarkable 2009 debut, “Because I Was in Love.” Onstage in front of the vast open space of the festival setting, her charms were lost, and she came across as Cat Power imitating Laura Nyro, but minus the bizarre spectacle of the former’s onstage melt-downs.

Just as uninspiring was the Tallest Man on Earth, a.k.a. Swedish singer-songwriter Kristian Matsson, who did his best Dylan circa ’65 imitation, but unfortunately lacked about 95 percent of ol’ Bob’s powers as a songwriter. But at least he moved around a bit more than Van Etten.

If one subtracted the significant power in this crowd of an endorsement by the Pitchfork Web site—a phenomenon parsed for the umpteenth time just the other day in The New York Times—there honestly was no justification for either artist holding such a prestigious festival slot. Both would have been better suited to a Tuesday night at Uncommon Ground.

By virtue of his own music and his championing of inventive underground hip-hop via the late, lamented Def Jux label, El-P certainly was deserving of his place on the bill, though it was ill-timed: The dense, dark sounds of his solo output and heavy themes of his lyrics would have been better suited to the nighttime hours, with a more party-hearty emcee taking his place in the sun. But after a rocky start, the artist his mom calls Jaime Meline found his groove and rode it out, helped by the fact that he seemed to be sober—not a given during his live shows by any means.

When the Liars took the stage at 5:30, it seemed as there finally might be some adrenaline pouring from the main stages. The New York dance-punks/noise-rockers started in rollicking, hard-hitting form, but their set all too quickly derailed into jammed-out pseudo-dub excursions that provided yet another excuse to yawn.

Part of it, sure enough, is the heat: Bands have to work even harder when it’s this sweaty to impart a sense of excitement. But Pitchfork organizers, fearing even more brutal temps tomorrow, are doing their part: I just got word that they’ve told vendors to drop the price of bottle water from $2 to $1. Stay hydrated, kids.