On the scene at Lollapalooza, day two: Eminem, Cee Lo, and (shhh! ) Foo Fighters

This is how the second day of Lollapalooza 2011 ended: With Wynonna Judd swinging her cramazing Ariel hair (she did not, alas, whip it back and forth) in the balcony during an epic two-and-half-hour “secret” Foo Fighters show at Chicago’s 1100-capacity Metro club.

But let’s start with how it began: Morning rain turned to sunshine in time for L.A. retro-soul shakers Fitz & the Tantrums‘ early-afternoon set on the main Music Unlimited stage. Even as already-tipsy showgoers began to wilt in the heat like drunk little flowers, frontman Michael Fitzpatrick, in a crisp cranberry suit, and his leopard-print-clad leading lady Noelle Scaggs, were extra-sharp, turning up the volume on their shake-and-stomp grooviness to fill the super-sized space and give the crowd the “hits”: “Don’t Gotta Work It Out,” “Moneygrabber”—even a Fitz-ified take on the Eurythmics’ “Sweet Dreams (Are Made of This).”

The soul train continued on the adjacent Sony Stage with flashback-R&B smoothy Mayer Hawthorne, who pleaded good-naturedly with the audience to take their camera-phone pics all at once and then “actually be in the moment and enjoy the show, I know it’s crazy.” After a cascade of snaps and flashes, they were duly rewarded with his shimmying cover of the Isley Brothers’ classic “Work to Do.”

And work to do there was, Mr. Hawthorne—which is why I had to miss the rest of the set to quick-hustle over to the mercilessly sun-scorched Bud Light stage for reunited noise-punk aggro-vators Death from Above 1979, who (sarcastically) played a snatch of AC/DC’s “Thunderstruck,” but thrashed more like a Canadian Pantera on Quaaludes. You know how they say, If it’s too loud, you’re too old? Maybe I was just too hot.

God Bless Patrick Stump, then, for landing at the mercifully shady BMI stage; the Fall Out Boy frontman followed his former bandmate Pete Wentz’s Friday side-project appearance with his own new solo incarnation. And though you’ve probably heard it before, dude looks like a whole new man—seriously.

Dressed like the world’s jazziest New Wave cater-waiter, Stump began the set with scat-like instrumental noodles (years ago during an interview, I remember him waxing on giddily about his love for Ornette Coleman; today, this made sense). His new sound, some out-there mix of funk and dandy, defies easy description; the closest I can come is to say that that James Brown and Bryan Ferry made a baby, and then put a bowtie on him.

In a day sometimes overly full of covers, Stump wins the gold medal for medleys for his set-crowning New-Jack mashup of Montel Jordan’s “This Is How We Do It,” Bobby Brown’s “Every Little Step,” Boyz II Men’s “Motownphilly,” and Bell Biv Devoe’s “Poison.” I’m not sure that what he’s doing with his original stuff will ever be commercial in the way that FOB was at their peak, but I’ve rarely seen a genuinely musical guy work that hard to bring that much show to a crowd.

Which is something you would think I would say about Cee Lo, right? Sadly, a set that should have been a gimme never quite got off the ground—maybe because the Goodie Mobster turned Gnarl Barkley turned solo and TV star delivered a set that was literally 90% covers: First Danzig’s “Mother,” and the Violent Femmes’ “Gone Daddy Gone,” then his Teddy Bears/B-52s collab “Choca,” and snippets of the White Stripes’ “Seven Nation Army” and Lenny Kravitz’s “Are You Gonna Go My Way.”

“Gimme some f—in’ energy!” he exhorted the listless crowd. “Don’t you dare let this wonderful outfit go to waste!” But after the Mad Max-ified crooner delivered his recent solo track “Satisfied,” it was back to the cover parade: “Welcome to the Jungle,” “Smells Like Teen Spirit,” Depeche Mode’s “Personal Jesus.”

The Gnarls smash “Crazy” briefly revived the field, though it slackened again during “Bright Lights Big City” and a brief venture into Journey’s “Don’t Stop Believing.” By the Time the grand “F— You” finale rolled around, it all felt a little strange; this was a set better suited to an intimate, late-night club crowd, not a massive mainstage festival slot.

Lykke Li, the crystal princess of Swedish avant-pop, had no such glitches at the Google+ stage; her audience stood rapt while she vacillated between fierce pagan priestess and sad pretty snowflake on favorites like “Dance Dance Dance,” “Little Bit,” the Burt Bacharach cover “Please Stay,” “I Follow Rivers,” and the always crowd-pleasing mashup of her “Youth Knows No Pain” and Kanye’s “Power,” which made Chicago just as happy as it made New York when I saw her deliver it Monday night at New York’s Central Park Summerstage.

Perhaps her Yeezy moment was a good segueway into Lolla Day Two’s ultimate set: Eminem at the Music Unlimited Stage. The real Marshall Mathers brought on early-day performer Skylar Grey, Bad Meets Evil cohort Royce da 5’9″, and even surprise guest Bruno Mars for a set heavy on hard-spat hits. Never one to go black tie, he stalked the stage in a hoodie and cargo shorts (the picture above is from an earlier show, due to time constraints) for “Won’t Back Down,” “Cleanin’ Out My Closet,” “The Way I Am,” and the Bruno-assisted “Lighters,” which sparked a sea of waving Bics and lit smartphones in the massive crowd.

I caught the decade-old, still-fresh “Stan,” but had to hear about his set-closing super-mix of hits (“The Real Slim Shady,” “Not Afraid,” “My Name Is,” “Without Me,” “Lose Yourself”) secondhand, because I was scrambling across town to catch the Foo Fighters’ not-so-secret show at the arthouse-theater-sized Metro.

Remember when I said that Lolla was a marathon? Then Dave Grohl is Usain Bolt, times nine million. “I hope you guys are ready for a long f—in’ night,” he growled as soon as the Foos took the Metro stage, “because we’re gonna do the whole new album, and then we’re gonna play a bunch of old s—.”

Grohl may be a funny man, but he was not joking: the band thundered relentlessly through the entirety of their recent, excellent Wasting Light before launching into a Foo’s Foo of greatest hits: “Learn to Fly,” “Everlong,” “Best of You,” “Monkeywrench,” “Times Like These.” (Special salute to Taylor Hawkins—you, sir, are the Tasmanian Devil of the drum kit).

Between songs, Dave did what he does best: crack a non-stop stream of gum and jokes. He shouted out Chicago landmarks (Cubby Bear, and seeing his “first obsession,” Naked Raygun, there), made fun of the Metro’s AC-impaired sweatbox past, riffed on Boogie Nights, compared bassist Nate Mendel’s ever-calm workmanship to “the guy on TLC’s Dirty Jobs,” and earned huge roars for saying of the band’s Sunday mainstage Lolla slot, “We’re proud to be one of the few headliners to play that stage without f—in’ computers.”

Patient readers, if you got this far, tell me will you be there tonight for the Foos’ iGadget-free set? What did you catch on Day Two? Did I hallucinate Wynonna?