7:03 p.m.: “I keep forgetting we’re meant to be on stage in 45 minutes,” One Direction’s Liam Payne announces in the hallways, a red Solo cup in one hand and a bandage wrapping the other -- the result of an incident that tabloids have already speculated to be a break-dancing mishap on Niall Horan’s 21st birthday or a workout-related injury.
8:00 p.m.: One Direction closes a brief, barely 20-minute set with “Best Song Ever,” which is perhaps most memorable for Harry Styles’ spontaneous splashing of water upon the crowd.
8:09 p.m.: When Fergie comes to the club, step aside. The Black Eyed Peas member samples her first proper solo single in eight years, “L.A. La La,” with a 15-second snippet that plays before her introduction of the next performer, Ed Sheeran.
Sure, “Don’t” is Sheeran’s active single from sophomore album, X, and it’s blazing up the airplay charts as we speak. But it’s also allegedly inspired by ex-girlfriend Ellie Goulding’s dalliance with One Direction’s Horan, so the set choice coming right after One Direction is a little cheeky, if ultimately coincidental. A pair of hip-hop interludes toward the end of Sheeran’s performance make the circumstance seem even loss plotted -- Chris Brown’s “Loyal” and Blackstreet’s “No Diggity” are both incorporated.
8:16 p.m.: Sheeran begins performing the chorus of Macklemore & Ryan Lewis’ “Same Love” acoustically, later introducing Macklemore himself as being on-hand to rap his verses. It’s not the first time the two musicians have teamed for the unlikely pairing on Macklemore’s song, but based on the feverish crowd reception, it could have been the best-received.
8:23 p.m.: Paramore's Hayley Williams says that the artist she most wants to meet tonight is… Iggy Azalea. "I bet she has a firm handshake!" Williams says, a sense of wonder in her voice.
Weezer are back on the scene after a nearly four-year absence, so Rivers Cuomo can afford to have a little fun at his catalog’s expense. That includes swapping out the “Hills” on Beverly Hills for a rotating lineup of words -- Kills and Chills being most prominent.
8:55 p.m.: Backstage, Anna Faris has to adjust the upper regions of her dress, and she asks husband Chris Pratt, "Are my breasts okay?" Pratt deadpans, "They're so okay."
Ed Sheeran Brings Out Macklemore | Calvin Harris Plays 'Blame'
9:01 p.m.: The members of Train pass by four cast members from Orange Is the New Black backstage, and while the Train guys are getting ready to take the main stage, "Orange's" Laverne Cox is busy absentmindedly singing Taylor Swift's "I Knew You Were Trouble."
9:10 p.m. The 5 Seconds of Summer boys shout out The 1975 backstage when asked about which rising rock bands they're most excited about.
9:25 p.m.: During Lorde's performance, most of the audience tweets that scroll across the ticker in the arena read something along the lines of, "I wish I had her hair!!!"
After letting several "G-g-g-g-g-g-g-unit!'s" echo throughout the backstage area, G-Unit supports first cadet 50 Cent onstage as he sinks into "In Da Club."
10:33 p.m.: Meghan Trainor didn't have time to perform her cover of Taylor Swift's "Shake It Off" onstage, but earlier, she informed Billboard earlier in the evening that she's long been a big T-Swift supporter.
11:00 p.m.: Having just played the Festival Village five and a half hours prior, Iggy Azalea is noticeably wiped from a long day in the sun. Though she plays a set virtually identical to the one performed earlier that day, she smiles (and twerks) her way effortlessly though fan favorites and smashes like “Black Widow” and “Fancy.”
11:26 p.m.: While 5 Seconds of Summer is introducing the next performer, Paramore, a group of young girls angle to get the best spot to see and possibly interact with the 5SOS lads when they're done. Fortunately for them, the band walks right by the group right after they're done their intro, leading to even more uncontrollable shrieks.
One Direction Lights Up Las Vegas with iHeartRadio Performance
11:46 p.m.: “I know I look like I'm 12 but seriously you guys, 10 years [together],” Hayley Williams says halfway into Paramore’s set, reflecting the band’s longevity. “Thank you so much for helping us get to play this very stage."
11:55 p.m.: Sure, it’s practically midnight, but guest Lil Jon has just one question: turn up for Calvin? He’s been tasked with working the crowd into a hyped-up EDM frenzy before closing headliner Calvin Harris takes the stage.
12:00 a.m.: Calvin Harris emerges in a giant console decked out with wall-to-wall speakers and a light system that surely comes with a hefty electric bill. His set choices are predictable (his own “Feel So Close” and “Summer” as well as Florence Welch’s “Sweet Nothing” and Ellie Goulding’s “I Need Your Love”) right up until festival closer "Blame" with an on-hand John Newman, who lends powerful, bellow-y vocals to a predictably barn-storming beat.
12:28 a.m.: No "We Found Love" from Calvin Harris, and no surprise headliner -- Prince was rumored to be showing up all weekend, but didn't make the trip to Vegas.