Jay Z performs at Coachella 2014

Jay Z performs onstage during day 2 of the 2014 Coachella Valley Music & Arts Festival at the Empire Polo Club on April 12, 2014 in Indio, California. 

Christopher Polk/Getty Images

Coachella 2014 rolled on Saturday (April 13) with epic performances by Lorde, Muse, Skrillex and headliner Pharrell Williams and guests including Gwen Stefani and Diddy among the dozens of acts rocking the desert. Take a time-stamped look at the 20 hottest happenings on the festival's second day. Find out during whose set Beyoncé hopped onstage for a surprise cameo, who welcomed Jay Z to the mic, which huge rock act covered Nirvana, and more.

Coachella 2014!
JAY Z NAS
Photos: Live at Coachella
Photos: Backstage at Coachella
Pharrell Rules with Snoop, Gwen Stefani
Jay-Z & Beyonce Invade
Lorde Makes Desert Debut
Muse Stays Epic, Covers Nirvana
Skrillex Takes Control
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Outkast's Coachella Comeback
23 Hot Coachella Moments Day 1
FULL COACHELLA COVERAGE

3:46 PM: Tyler, The Creator is spotted heading back to the parking lot with his entourage, but he's far from done with his Saturday Coachella experience -- seven hours later, he'll be onstage with Pharrell Williams.
 
4:13 PM: Rising R&B vocalist Banks covers Aaliyah's classic single "Are You That Somebody?" after saying that the song "made me feel like butter." She even rapped the Timbaland verse!

4:46 PM: Right after CHVRCHES' Martin Doherty took over lead vocals for "Under The Tide," there was a debate between whether a first-row audience member had yelled "Fuck yeah, Martin!" or "Fuck you, Martin!" after the song. "I hope it wasn't fuck you!" said lead singer Lauren Mayberry, sounding genuinely concerned for her bandmate's feelings.

5:57 PM: In the Sahara Tent, GTA drops System Of A Down's "Chop Suey!," creating a loop of the word "die" and letting the closeted rock nerds in the dance tent go bananas.
 
7:24 PM: Right before Future Islands slashes through fan favorite "Tin Man," a real tin man -- that is, a guy dressed in a silver "Wizard of Oz" costume -- hops on a friend's shoulders near the front row and delights singer Samuel T. Herring. Two minutes later, the tin man is crowd-surfing towards the Baltimore band.

8:16 PM: "This was the first big thing I ever booked," Lorde tells the crowd about Coachella, which she agreed to play last May, long before "Royals" hit No. 1. The 17-year-old does not hide her excitement about being on the Coachella bill: "Every time we do something like this, we try to tell ourselves that we're so lucky to be here. This is so mental."
 
8:57 PM: Pixies take the Mojave stage for their set -- a last-minute lineup addition announced only four days prior. The quartet (now completed by new bassist Paz Lenchatin) has new music to promote, but they give the crowd what it wants, kicking off it set with a succession of old-school favorites “Bone Machine,” “Wave of Mutilation” and “Head On.”
 
9:14 PM: Solange has played a large number of festivals in support of her 2012 "True" EP, but Coachella 2014 is special for including a gasp-worthy cameo from her big sister. Beyoncé appears onstage to dance next to Solange for the finale of "Losing You," the Knowles siblings standing side-by-side and committing to a dance routine while a stampede of onlookers push closer to the stage in order to gaze and take photos.

 
9:40 PM: It's always rare for a band to open their set with their best-known song, but Queens of the Stone Age do just that by burning through their breakthrough hit "No One Knows" first and weeding out the pretenders in the crowd.

PARIS HILTON at EMPIRE OF THE SUN at COACHELLA

10:03 PM: Need inflatable animals? The Empire of the Sun crowd has plenty to spare: blow-up flamingoes, zebras and sharks can all be easily spotted floating in the audience (which includes Paris Hilton) as the Australian group plays on.
 
10:44 PM: The Dismemberment Plan, slated to hit the stage at 12:05 AM, tweets, "What are some goofy dudes from DC doing playing at the same time as Muse, Nas, Skrillex, and the Pet Shop Boys. Crazy. Well let's do this."

10:46 PM: It only takes two songs to get Pharrell reaching back into his remarkable discography. After playing recent tracks "Lose Yourself to Dance" and "Come Get It Bae," Pharrell calls "Let's take it back," and grins slyly when the "Frontin'" beat drops.

10:54 PM: The cold wind is picking up, but Nelly doesn't mind -- the St. Louis rapper joins Pharrell for his Neptunes-produced smash "Hot In Herre."

11:08 PM: Snoop Dogg strolls out to join Pharrell for "Drop It Like It's Hot" and "Beautiful."

 
11:20 PM: Pharrell's show was star-studded before its major guest turns up, but the arrival of Gwen Stefani produces amazed shouts as she immediately jumps into "Hollaback Girl."
 
11:36 PM: Pharrell ends his set with a massive version of "Happy," in which Busta Rhymes is dancing to his right side and Tyler, The Creator is hugging his left side.

11:57 PM: Muse's Matt Bellamy dedicates a cover song to "a great singer who died 20 years ago," and the group plays an epic version of Nirvana's "Lithium" in honor of Kurt Cobain.

 
12:08 AM: Pet Shop Boys bring back the ‘80s when they drop their signature hit “West End Girls” in the Mojave tent. Fans who weren’t even born when the song went no. 1 in 1986 groove respectfully in the field.

SKRILLEX at COACHELLA</a><p><span style=12:23 AM: Skrillex’s playing from inside a giant anime jet-fighter, makes a crazy Sahara tent go even more mental when A$AP Rocky takes the stage for their bass-heavy collaboration “Wild for the Night.”

12:42 AM: After performing his landmark album ‘Illmatic’ in its entirety, Nas welcomes Jay Z to the stage to perform their 1996 collaboration “Dead Presidents II.”