7:34 p.m. PT: Christina Aguilera hits the stage to welcome "rock icons" Green Day back to the iHeartRadio Music Festival (they last performed at the Vegas fest in 2012). The rockers kick things off with their 2004 President Bush-skewering hit "American Idiot," this time changing some lyrics to take aim at President Trump instead. This time around, they replaced "I'm not a part of a redneck agenda" with "I'm not a part of a MAGA agenda," calling out Trump's favorite red-hat motto "Make America Great Again." (Read more about it here.) Green Day rounded out their set with "Holiday," "Basket Case" and "Boulevard of Broken Dreams," along with a couple of spins of their latest single, "Father of All… ."
7:56 p.m.: French Montana was the lone hip-hop artist on the Friday night bill, and he repped the genre well with his biggest hit to date, the Billboard Hot 100 No. 3 smash "Unforgettable."
8:21 p.m.: How lucky are we that Ann and Nancy Wilson are still wailing after all these years? The T-Mobile Arena was a fittingly massive venue for the sisters' unstoppable vocals. Case in point: "Crazy on You."
8:49 p.m.: Oh, did we say French Montana was the only rapper on the bill? Scratch that, because a surprise Lil Nas X has just made his way to the stage to perform his top 20 Hot 100 track "Panini" backed by DJ Obscene. But wait, just "Panini"? Really? No room for a certain 19-week record-breaking No. 1 hit?
8:55 p.m.: Camila Cabello kicks off her set with the live debut of "Shameless." A few tracks later, she also gifts the crowd with the live debut of its partner single, "Liar." Oh, and she pulled double-duty on her No. 1 duet "Señorita," in the absence of Shawn Mendes. (More on that here.) She also played "Never Be the Same" and "Havana" in her five-song set.
9:26 p.m.: Of course, Lil Nas X is back with "Old Town Road." We wouldn't want it any other way.
9:37 p.m.: Their Vegas residency only wrapped back in April, but yes, technically Backstreet is, indeed, back in Sin City. One of the highlights of the Backstreet Boys' high-energy set was the choreography for "Larger Than Life," the song that gave that residency its name.
9:48 p.m.: In the only time we witnessed a sing-along backstage, dozens of reporters and photographers break into song on the chorus of BSB's "I Want It That Way." They couldn't help themselves.
10:15 p.m.: "Damn, y'all lookin' good tonight," Tim McGraw tells the iHeart crowd. (Judging by the screams in response, they think the 52-year-old crooner looked pretty good in his halfway-unbuttoned black shirt too.) "My name's Tim McGraw and I'm your country guy." This intro (after he had already performed a few hits, including 2013's "Truck Yeah") led into McGraw talking about some of his inspirations. One of those inspirations was The Cars, whose song "Drive" he just released a cover of late last month, weeks before frontman Ric Ocasek was found dead in his New York home. "We're losin' a lot of good ones," McGraw laments before performing "Drive."
10:25 p.m.: McGraw also debuted a brand-new song during his set: "Way Down" alongside country rookie Shy Carter.
10:33 p.m.: Fletcher performs two songs as part of a Taco Bell-sponsored set, wrapping things up with her breakthrough hit "Undrunk" -- her first every entry on the Hot 100.
10:43 p.m.: What is there to say about Cage the Elephant's performance? Well, aside from frontman Matt Schultz's truly impressive vocal and physical acrobatics throughout, it also should be noted that he stripped off layers of clothing throughout the set, culminating with the removal of two pairs of pants down to a wrestling-singlet-like bodysuit. And as if that all wasn't bonkers enough, Schultz took a dramatic spill off the stage and the band didn't miss a beat.
11:21 p.m.: So many song debuts! Hootie & The Blowfish also break out a new one, from their November comeback Imperfect Circle, called "Hold On."
11:27 p.m.: Hootie also took their performance to the disco, somehow transitioning from the 1995 hit "Only Wanna Be With You" to Kool and the Gang's "Get Down On It," with Darius Rucker's vocals doing the heavy lifting.
11:57 p.m.: More firsts! Halsey performs her brand-new song "Graveyard" for the very first time after making the audience promise they were worth the debut (they passed). The pop star also did her part to help environment by encouraging everyone to get a reusable water bottle like the one she drank from between songs, and then just throwing that bottle out into the crowd so one fan could get started on their greener path. "Let's save the planet," she said. "Let's keep it sexy, folks."
12:11 a.m.: Steve Aoki closed down the whole show, and he had some epic guests along for the ride. Along with Darren Criss -- who joined Aoki for their dance remake of Dave Matthews Band's "Crash Into You" -- there was an unannounced cameo from Backstreet Boys for "Let It Be Me." Oh, and a little K-pop group called Monsta X, who hit the Vegas stage for "Play It Cool."