Coachella Kicks Off, Paul McCartney Drops By, Plus Cee Lo, Lauryn Hill – Danny DeVito!

The Cute Beatle crashes a DJ set, Danny DeVito takes the stage, and Cee Lo Green shows up late and gets pulled offstage early

The 2011 Coachella Valley Music & Arts Festival kicked off on Friday, as Danny DeVito danced, Cee Lo Green got there late, the main stage was bigger and flashier than ever before, and by Saturday almost 100,000 fans had sweltered in the desert sun.

Oh, and a guy named Paul McCartney showed up unexpectedly during a DJ set by Afro Jack.

Coachella groundsMcCartney, who headlined the festival in 2009, set the Twitterverse abuzz late Friday when news surfaced that he dropped in on the Sahara tent to guest in Afro Jack's set – though many people took it for a joke at first, particularly when photos didn't surface.

("This is when annoying cell phone pic snapping would be useful," tweeted @scriptgrrl.)

But the Cute Beatle was indeed on the grounds of the Empire Polo Club in Indio, California, sitting in with Afro Jack and watching other groups and, reported @shornstein, "doing the noodle dance backstage while the Black Keys are rocking out!"

Performers on Friday, the first day of the three-day festival in the desert east of Los Angeles, included the Black Keys, Kings of Leon, Chemical Brothers, Interpol, Cold Cave, Robyn, Ozomatli, the Killers, Flogging Molly and Cee Lo Green, who caused the day's biggest fuss when he showed up half an hour late for his 4:50 p.m. set.

Cee Lo GreenAfter explaining "I just landed," Green (right) put the onus on the promoter: "It ain't my fault. They should have … given me a better time slot." After 20 minutes and five songs, he changed his tune and said, "It's my fault, blame me," before he was forced off the stage in the middle of his version of Journey's "Don't Stop Believin'."

He wasn't the only act on the main stage to be tardy: his successor on the stage, Lauryn Hill, started 15 minutes late, and then spent a lot of time asking that people "straighten out the energy" before she began the first song of what was by all accounts a strong, high-energy set.

Celeb fans at the annual fest included Paris Hilton, Katy Perry, Rosanna Arquette, Tara Reid, Whitney Port, Ashley Greene, Robert Downey Jr., Vanessa Hudgens and Josh Hutcherson, and Alexander Skarsgard and Kate Bosworth. Lindsay Lohan was there, too, but we probably didn't need to tell you that.

Also read: Coachella Party Scene: Where to Go When You're In the Desert

Tweeted @bobbyhundreds: "All the hipsters are headed off to Coachella. Here in L.A. we call it 'Spring Cleaning.'"

Also among the, um, hipsters was regular Coachella visitor Danny DeVito, who danced in the wings, then took the stage during a set by the ska band the Aquabats.

New innovations this year included a high-tech stage with lighting that reacts to the crowd when bands aren't performing, as well as custom lighting installations in the performance tents. The innovations, Intel's Deborah Conrad told the AP, mark "a convergence of art and technology in a way that's truly a first."

Floggy Molly stageAt the adjacent campground, meanwhile, the 8,800 spots for people and tents were set amidst a farmer's market, an arcade, a roller rink and a spot for yoga classes.

Security was stepped-up this year after rampant gate-crashing and counterfeiting problems at previous festivals, making the trip to the site even more arduous than usual.

The journey from the will-call center to the site's parking lots, wrote Gerrick D. Kennedy in the L.A. Times' Pop & Hiss blog, took two hours and "became an everyone-for-him-or-herself scene out of some cheesy rock-themed, post-apocalyptic flick."

Coachella continues on Saturday with the Arcade Fire, Bright Eyes, Animal Collective, Mumford & Sons, Gogol Bordello. Erykah Badu and Broken Social Scene, among others. Sunday's headliners include Kanye West, PJ Harvey, the Strokes and Duran Duran.

Also on Sunday: Fistful of Mercy, a new group featuring Ben Harper, Joseph Arthur and Dhani Harrison, the son of the late Beatle George Harrison.

Maybe Sir Paul will stick around for that one.

Video from Coachella is streaming live at Coachella's YouTube channel.

(Photos by Getty Images. Coachella grounds, Cee Lo Green: Kevin Winter. Nighttime stage: Frazer Harrison. Danny DeVito with Aquabats: Charley Galley.)