As a warm-up to its big comeback gig closing out Lollapalooza Sunday night, Soundgarden packed Chicago's intimate Vic Theater Thursday (Aug 5). While the original four-piece ably served up two hours of the muscular, sludgy rock they made their name on 20 years ago in Seattle, the capacity crowd was surprisingly subdued.

"I shouldn't be able to hear myself think, you should be drowning me out," frontman Chris Cornell quipped before 1996's "Burden In My Hand." "Lots of people are mad they aren't here. If they were here, they'd be screaming."

Replacing the rampant headbanging of Soundgarden's days of yore was more of a vigorous nodding along, though pockets of pogoing, singalongs and the occasional bout of crowdsurfing erupted for favorites like 1991's "Jesus Christ Pose" and 1994's "Spoonman."

Playing just its second gig since reuniting several months ago (and 13 years after calling it quits), the band was sonically in fine form. The 25-song set, which boasted tunes from "Rusty Cage" to "Outshined" to "Fell On Black Days" to "Black Hole Sun," filled the theater with the powerful combination of Kim Thayil's Drop D riffs, Ben Shepherd's eyelash-vibrating bass, and drummer Matt Cameron's intricate, machine-gunning beats, all topped by Cornell's still quasi-operatic metal yell. Soundgarden seemed keen on capturing the gig for posterity. Mics were aimed at the crowd, suggesting that a live reording was afoot. Famed rock photographer Danny Clinch had free reign all night. And shooting the show was one of the videographers from the Pearl Jam camp -- Cameron also being Pearl Jam's drummer.

In the spotlit semi-darkness of it all, there was a bit of an odd sensation of stepping back in time. With his baggy shorts and classic, shoulder-length locks, 48-year-old Cornell looked little different onstage from his 28-year-old self. Only Thayil, whose beard has gone gray and who favored a fedora, seemed to show the obvious effects of time. If you squinted your eyes during the unforgivingly raucous "Face Pollution," you might have slipped back to 1991 for four minutes.

But what does that all mean for Soundgarden's set this Sunday, in front of tens of thousands of Lollapalooza 2010 fans? Maybe that crowd and the band's energy will feed off of each other, building a monster feedback loop that the Vic audience just wasn't able to incite on a Thursday night.