CHICAGO -- Perry Farrell's good luck ran out on Saturday (August 4) when the predicted rain finally fell from the sky to the tune of Karen O's manic wails. But the downpour surely didn't dampen the spirits of the Lollapalooza crowd, which grew significantly on this, the festival's second day.

(Get your Lollapalooza fill: Watch the Roots' ?uestlove, Perry Farrell, Cold War Kids, Stephen Marley and more chill in the shade with Tim Kash and [article id="1566350"]see snaps of the Yeah Yeah Yeahs, Daft Punk, M.I.A., the Rapture and more.[/article])

Instead of bringing down the mood, the rain kind of cooled things off and made for a nice, humid vibe during Interpol's closing set, as lights were hit with rain, sending steam into the air. Taking the stage like a gang of new-wave Black Barts, Interpol closed out day two of Lollapalooza with style, a boatload of low-end and the velvet-rope-jumping swagger they've become famous for. The thudding bass of dressed-in-black Carlos D. and the molar-rattling kick-drum of Sam Fogarino set the crowd dancing (and doing other things) during the see-sawing "Slow Hands, " as the somber group kicked off a 70-plus-minute set that alternated between propulsive rockers and moody meditations.

It was hard to gauge just what inscrutable singer Paul Banks -- also, of course, dressed in black pants, black shirt and sporting a black wristband -- was thinking, since his blond mop of hair was hanging in his face for much of the set and he didn't speak except for a perfunctory hello to the rain-soaked crowd.

All the fans needed to hear was the group's string of midset narcotic lullabies building up to the stadium-size anthem "Evil, " which has "instant classic" written all over it. From the Pixies-like walking bass intro to the rat-a-tat drums, Banks' just-behind-the-beat singing and the slashing/watery guitar line from Daniel Kessler, the tune lived up to the band's rock and roll desperado look. And when Carlos D. held up his bass to play his part as if it were a giant Roman Candle, it almost made you wish some sparks would fly out of it.

The rain let up just in time for Muse's closing set, which was a visual stunner: 10-foot panels of pulsating lights, with blinding strobes, and gigantic screens, projecting strange sci-fi (think "Tron") and politically tinged imagery. Opening with "Take a Bow," a powerful commentary on both President Bush and former Prime Minister Tony Blair's decision to enter Iraq, Muse reinvigorated the soggy crowd. The band couldn't have been more on -- every note was executed masterfully, making this the perfect ending to a day full of high points.

Next came "Hysteria, " followed by "Supermassive Black Hole" and "Butterflies and Hurricanes." Frontman Matthew Bellamy's haunting vocals put an interesting spin on the band's only cover of the night, Nina Simone's "Feeling Good. " The anthemic performance continued with "Apocalypse Please," "Invincible," "Starlight" and "Time Is Running Out," all of which had the audience mesmerized -- these guys put on a huge rock show, which ended with the triumphant "Knights of Cydonia." Muse set the bar pretty high and will be a tough act to best on Sunday.

The Yeah Yeah Yeahs certainly brought the power as well. As we've learned from musical history, rock stars are born, not made. And whatever DNA contributed to the makeup of the Yeah Yeah Yeahs' Karen O must have been one wicked batch. The dynamo lead singer of the indie champs stole the show Saturday with a fashion-forward set that had more costume changes than a Cher extravaganza and some rebel yells that threatened to rattle the windows of the skyscrapers on the Chicago skyline.

Strutting onto the stage in a giant silver cape with black Charlie Brown-style wavy stripes and silver tassels hanging off the neck, O took center stage and eyed the audience before dropping the cape to reveal an all-black leather outfit -- bustier, shorts, fingerless gloves, some kind of skirt -- accented by silver high-tops and black criss-cross leggings. As the band ripped into the monster-stomping "Sealings, " with O yelling, "Shoot, shoot out your mouth, " she exuded rock-star cool from the first moment, owning the audience.

The punk blues of "Honeybear" lurched around like a drunken, well, Lollapalooza fan, speeding up, slowing down and dropping into grinding dirges as the rain began to fall. O messed with her stage getup throughout the set, putting on a feathered mask with silver tassels, draping her face in a silver shawl, ripping her gloves off with her teeth and smearing her red lipstick around so it looked like she'd been punched in the mouth.

The day started off way more mellow, but no less ominous, with a disco-dance-of-death set from Clap Your Hands Say Yeah, whose singer, Alec Ounsworth, sounded less like former Talking Heads frontman David Byrne -- whom he is often compared to -- and more like a helium-voice preacher. The jangly sounds of "Yankee Go Home" (with the unforgettable refrain "Yankee go, Yankee go, Yankee go home") morphed into a spooky waltz that sounded way too creepy to play in broad daylight -- and the day had plenty of creepiness.

After opening by singing a cappella, accompanying herself on percussion by tapping on the microphone rhythmically, oddball singer/songwriter Regina Spektor paid tribute to a legendary artist who would take the stage a few hours later, Rock and Roll Hall of Famer Patti Smith, by playing her song "Poor Little Rich Boy," which, in turn, references Smith's version of the Who's "My Generation." Again improvising for percussion, Spektor banged on a chair with a drumstick while playing piano with her left hand during the spare tune. Spektor also stopped her set midway into the second song, "On the Radio," when she spotted a fan who had passed out in the middle of the crowd, urging security to get her some help. "I think there's someone sick," she said in her kewpie-doll voice.

Snow Patrol also reached out to a fellow Lolla act during their set with a duet with Silversun Pickups bassist Nikki Monninger, who filled in for Martha Wainwright on the track "Set the Fire to the Third Bar." The overly polite Scots (frontman Gary Lightbody thanked the audience after every song the band performed and even dedicated each track -- to the crowd, to the other bands on the bill, to Monninger "for being so sweet") performed a veritable best-of from their growing catalog, including songs like "Run," "Chasing Cars" (the closing chorus of which the singer left to the audience), "How to Be Dead" and "Spitting Games," which Lightbody dedicated to a man in the front row, who was dressed, from head to toe, in a Spider-Man costume and waving an Irish flag to catch the singer's attention.

About 20 seconds into the song, the Spider-Man wannabe made a beeline for the stairs leading up to the stage but was tackled by a team of security guards before he could make it past the third step. As the final notes of "Spitting Games" reverberated across the open field, echoing off the trees, Lightbody, disappointment in his voice, muttered, "Well, I guess he wasn't the real Spider-Man."

One of the warmest receptions of the day was bestowed upon the Cold War Kids, whose set was impassioned, flawless, and, at times, soulful. There wasn't a person in the fist-pumping audience who wasn't singing along with frontman Nathan Willett -- doing his best Joe Cocker impersonation -- during "Hang Me Up to Dry."

Next up was this generation's answer to P-Funk, the Roots, arguably the tightest band here at Lollapalooza. The band turned up the funk with a genre-spanning medley filled with chunky bass, virtuoso guitar (that inspired some rapturous hyperbole from our blogger), mind-boggling drum solos and a complete horn section. The Roots shifted effortlessly, and without skipping a beat, from Sugar Hill Gang's "Rapper's Delight" to Iron Butterfly's "In-A-Gadda-Da-Vida," then to the Gang's "Apache" and Biz Markie's "Just a Friend." Next came ODB's "Shimmy Shimmy Ya," Salt-N-Pepa's "Push It" and MIMS' "This Is Why I'm Hot."

The band's performance even attracted the likes of Geico's Caveman, who made his way through the sea of sweaty flesh in front of the stage, giving high-fives and posing for pictures with the hippies that saturated the crowd. The Roots ended things with a cover of the New Birth's "I Can Understand It," which then faded into a captivating James Brown medley. Still, all the folks here had to contend with was a slight drizzle, but the clouds above Chicago are getting darker, and more and more engorged with rain.

Meanwhile, over on the MySpace stage, the Hold Steady geared up and turned out perhaps the most entertaining performance thus far -- if only because of how much fun these guys obviously have when they're in their element. The blood rushed to Steady frontman Craig Finn's face as he spit out the lyrics to fan faves like "Chips Ahoy!," "First Night" and "You Can Make Him Like You." And appearances aren't deceiving in this band's case -- these dudes absolutely love being onstage.

"We played here last summer, and I said it was the most fun I'd ever had before 3 p.m.," Finn, who was sporting a Ron Gardenhire jersey, explained. "This is shaping up to be the most fun I've had in my life."

Sherwood started off the day on the MySpace stage with a feel-good, feedback-filled set that included a confession. "We've never been to a Lollapalooza before," said frontman Nate Henry. "I'm sorta confused as to how this happened."

The first act to hit the main stage was Ontario, Canada's Tokyo Police Club, a young indie/ garage-rock outfit whose every song seemed to end on a dime. The band woke the crowd up with a heaping helping of bombastic drum blasts, tinny guitar squeals and thick, syrupy bass lines. And despite the early hour, the turnout for the Club was strong. "It's shocking to see so many of you here," noted frontman Josh Hook before the band launched into the explosive "Box." The crowd showed their appreciation, applauding loudly for the Lolla virgins.

Later on, Minneapolis rockers Tapes n' Tapes churned out a driving set that was so loud it nearly blew the MySpace stage's amps -- but not loud enough to scare away at least three dads in attendance, who traipsed through the crowd with infants strapped to their chests. The highlight of the band's volatile performance was "Beach Girls," during which drummer Greg Alsop hammered the skins as if the fate of the free world depended on it.

I'm From Barcelona also warmed up the already-warm crowd with a memorable pre-noon set. The 20-plus-member Swedish band (which included everything from a tuba player to a percussionist with banana-shaped maracas) nearly topped the Polyphonic Spree's Friday set when it came to stage-filling energy and enthusiasm. With songs about chicken pox ("You can't have it once you've had it") and cassettes, lead singer Emanuel Lundgren led the wacky pop/polka powerhouse through a set that had crowd members' hands waving in the air and included a kazoo solo from a fan who claimed he'd never had the pox.

The pre-lunch hours also brought a rare bit of soul to the proceedings, with a funky set from sets from Georgia's Ryan Shaw, a dreadlocked Sam Cooke-alike who had to raise the roof even higher to with the sound bleeding over from dour rocker Pete Yorn on an adjacent stage.

And if you haven't heard of R&B singer Kevin Michael yet, there's a good chance you will soon. Though he played to a sparse crowd, the young singer with the towering afro and a voice that mixes the soulful side of Michael Jackson with a hip-hop edge, played (tellingly) to a mostly female audience during his short set. Unfortunately, hometown hero Lupe Fiasco didn't show up to reprise his cameo on the hand-clapping banger "We All Want the Same Thing," but Michael's keyboard and guitarist/beatboxer band held it down ably as the buff crooner jumped down off of the stage to get some face time with his adoring female fans.

Make sure to stick with MTVNews.com for your Lollapalooza news all weekend.

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[This story was originally published on 8.4.07 at 6:11 p.m. ET.]