Lollapalooza 2012: 10 Best Moments of Day 2

So it's not technically a "best" moment, but we'd be remiss to not mention the minor hiccup of having to evacuate 80,000 people from Grant Park due to an oncoming storm. It was the first time in the festival's eight-year stint in Chicago that organizers have had to clear out the festival, but thankfully, city officials deemed the site safe and Lollapalooza was back on 2 1/2 hours later. Bummer for Alabama Shakes, B.o.B and the other acts who were forced to cancel their sets, but luckily Saturday wasn't a complete, er, wash.

With many in the crowd taking the unplanned delay in stride, some festivalgoers turned crisis into opportunity by slathering themselves in mud. Saturday, part two, turned out to be more Woodstock '94, when heavy rains birthed a new tribe dubbed "mud people," than Woodstock '99, when poor planning and accusations of price-gouging led to arsons, rioting and reports of sexual assault. Good on you, Chicago.

We've got the full review of Frank Ocean's mesmerizing set on Fuse.tv, but Ocean's opening track—a cover of Sade's 2000 hit "By Your Side"—stands as a moment of its own. Few singers would have the ability or courage to tackle one of the most respected vocalists of the past 25 years, but Ocean did the track justice, retaining the former's romantic core while adding his own unique phrasing.

So many potential moments here: The dancing sign language interpreter. The retro-soul singer's request to turn to your friend, hug them and tell them that you love them. But we're going with Blacc's plan to turn the entire main stage crowd into two giant 'Soul Train' dance lines. "I used to watch that show to see all the hot, new R&B artists," said the singer, whose blend of funk, soul and pop was a festival highlight and the perfect accompaniment to a then-sunny afternoon. The crowd dutifully obliged, though one side was a bit off. "I didn't say a conga line!," yelled Blacc, genially. Hey, it was the thought that counts.

At Hip Hop Workshop at Kidzapalooza, children were able to get on a stage with a DJ and MC and learn the basics of rapping and beatboxing. "It gives kids the experience of being on stage," said host MC Phenom, who records each track and e-mails it to the fledgling rapper's parents. Here, "MC Henry," age 3, takes his first step toward mastering the art, rhyming "B" with "C" and already proving more adept than some professional rappers.

"How many people know what it means when I say, 'No '60s'?," asked JEFF the Brotherhood frontman Jake Orrall, to a light smattering of applause. "F*ck! That's like 12 people. Well, we're going to play that next," as the band ripped into "Noo Sixties" from 2006's 'Castle Storm.' And while the crowd may not have known it before, it was hard not to get hooked by the track's ramshackle vibe. Honorable moment mention: Orrall's jorts/denim vest ensemble.

On the heels of releasing 'Four,' their first album in four years, frenetic UK rock group Bloc Party took the stage as thousands of fans sloshed through the mud to watch them perform. During 2005's "Positive Tension," a giant circle formed in the crowd as a group of fans started a mud mosh pit. Laundromats everywhere rejoiced.

The School of Rock—yes, the same one that inspired the Jack Black movie of the same name—has been a consistent presence at Lollapalooza for years. Above, this year's class is way more talented than we'll ever be, taking on everything from the Kinks' "You Really Got Me" to Pink Floyd's "Hey You" to Stevie Wonder's "Living for the City."

How well-received was Calvin Harris' set? The producer/DJ's reign extended past the field at Perry's Stage into the adjacent street, where Columbus Drive, usually just a route between stages, burst into a spontaneous dance party. Those wanting to get by are probably still grumbling, but those involved have a moment for life.

This photo was taken hours before Hot Dog tragically got soaked and rendered inedible by Saturday's thunderstorm. Mustard is said to be inconsolable.