Mariah Carey & Las Vegas 'Belong Together,' Plus More Highlights From iHeartRadio Music Festival 2018 Day 1

Rich Fury/Getty Images for iHeartMedia
Mariah Carey performs onstage during the 2018 iHeartRadio Music Festival at T-Mobile Arena on September 21, 2018, in Las Vegas, Nevada.

Ludacris shows up for two surprise sets after Sam Smith cancellation, Childish Gambino re-creates his eye-popping "This Is America" choreography & more.

iHeartRadio Music Festival always runs the genre gamut, making hard left turns from the good-ol'-boy country of Jason Aldean to the sequin-covered R&B of Mariah Carey to the Dirty South hip-hop of Rae Sremmurd to the gypsy rock of Fleetwood Mac -- and yet it works, because the artists all have one destination in common: the top of the Billboard charts.

Take a run through Friday night's chart-topping day 1 roster -- which also included Childish Gambino, Jack White, Panic! at the Disco, Kygo and a surprise Ludacris -- and stay tuned for Saturday night's (Sept. 22) equally star-studded day 2. (All times in Pacific Time.)

7:28 p.m. PT: Jason Aldean speaks to reporters backstage, opening up about his return to Las Vegas nearly a year after the deadly Route 91 Harvest music festival, his latest Billboard 200 No. 1 album Rearview Town, and becoming a dad for the fourth time. His youngest is 9 months old, so Aldean and wife Brittany will have two kids under a year and a half when the new baby is born. "Now we've got two cribs on our bus, which in the early days of my touring career, I never thought I would say that," he laughs.

7:31 p.m.: Before things kick off inside T-Mobile Arena, there's plenty of action backstage, with Fifth Harmony's Dinah Jane, Lance Bass and Paula Abdul all giving interviews. There's also a mess of characters from the Bachelor universe, including the recently engaged Ashley Iaconetti and Jared Haibon and previous leads Ben Higgins and Nick Viall. When asked who from the weekend's lineup should join the Bachelor franchise, Viall has the perfect pick: "Sam Smith -- he's always looking for love." As we would later find out, Smith had to cancel his scheduled iHeart performance, so the festival -- and his search for love -- will have to wait.

8 p.m.: Fleetwood Mac start the night on an epic note, with the pounding intro of "The Chain" pulsating through T-Mobile Arena and vibrating the seats.

8:06 p.m.: Christine McVie takes the lead on "Little Lies," and Stevie Nicks shimmies over to the drum set to shake her tambourine with Mick Fleetwood to end the track.

8:11 p.m.: In the absence of longtime lead guitarist Lindsey Buckingham, Fleetwood debuted a new lineup on the road earlier this month, and the iHeart crowd got a taste of Crowded House frontman Neil Finn's contributions with his strong vocals on "Second Hand News."

8:14 p.m.: Every concertgoer was given an LED bracelet when they entered the festival, and the bangles light up for the first time for the dreamy opening strains of "Gold Dust Woman."

8:19 p.m.: Stevie twirls in her black gown and golden shawl and gives the crowd life

8:23 p.m.: They're not doing the condensed version of "Gold Dust" for this radio crowd: The song wraps after a leisurely nine-plus minutes.

8:24 p.m.: Fleetwood Mac joyfully wrap up their set with "Don't Stop," leaving countless hits on the table.

8:54 p.m.: Childish Gambino re-creates his (literally) eye-popping "This Is America" video choreography onstage for his second song of a far-too-brief three-song set, which was sandwiched by "Summertime Magic" and the sultry "Redbone." The irony was thick as Donald Glover repeated the line "get your money" in front of the corporate iHeartRadio crowd.

9:06 p.m.: Jason Aldean and Nashville radio host Bobby Bones welcome dozens of Vegas police officers, firefighters and EMTs to the stage to salute their work in responding to the Route 91 tragedy on Oct. 1, 2017.

9:10 p.m.: Before introducing Jack White, Ryan Seacrest lets the crowd know that Sam Smith will not be performing due to "unforeseen circumstances."

9:37 p.m.: Now that The White Stripes' "Seven Nation Army" has become an unlikely stadium anthem, Jack White appropriately pulls it out at T-Mobile Arena, the home of the NHL's Las Vegas Golden Knights. The crowd knows just what to do as White's band pulls back and lets the "Ohhh-oh-oh-oh-oh-ohhh-ohhh" chant ring through the arena.

9:39 p.m.: "God bless you. You've been incredible. And I've been Jack White."

9:47 p.m.: Rae Sremmurd storms the stage with energy to spare to kick off their set with "No Type," hitting the crowd with "Powerglide" and, of course, their Billboard Hot 100 No. 1 hit "Black Beatles" over the nonstop 20-plus-minute set.

10:10 p.m.: The DJ queues up DJ Khaled's "All I Do Is Win," and all of a sudden surprise performer Ludacris is onstage rapping his intro verse. He follows it up with "Stand Up" and Usher's "Yeah!" for the perfect unexpected treat.

10:19 p.m.: Unofficial Las Vegas ambassador Brendon Urie hits the stage, looking his showman best in a perfect sequined jacket to kick off Panic! at the Disco's performance with the "Rock Lobster"-sampling "Don't Threaten Me With a Good Time" and a handful of well-placed shrieks.

10:26 p.m.: "I wrote this song hoping to do it with Sinatra," Urie says to introduce "Death of a Bachelor," the title track from Panic!'s 2016 Billboard 200-topping album.

10:33 p.m.: After ripping through "Say Amen (Saturday Night)," Urie tells the crowd, "See? We did it, even though it's Friday!" The band ends with the one-two punch of breakout hit "I Write Sins Not Tragedies" and jock jam "Victorious."

10:42 p.m.: Luda is back! This time he runs through "How Low," "Money Maker" and "Move Bitch."

10:51 p.m.: After his heartfelt Vegas tribute earlier in the night, Aldean is ready to kick things into party mode, starting his set with "Lights Come On" and also doing the upbeat numbers "She's Country" and "My Kind of Party." It wasn't all uptempo though: A smattering of couples took to the aisles to slow-dance to his latest romantic hit "You Make It Easy."

11:01 p.m.: Aldean also performs "Dirt Road Anthem," and after the pair of surprise Ludacris sets, it was even more of a surprise that Luda didn't come out to do his guest verse on the rap-country track, though the pals did catch up backstage.

11:18 p.m.: Mariah Carey arrives for a showstopping performance, showing off her impossibly tiny waist in a blue sequin mini-dress and starting the night with "It's Like That." The set list is reliably festive, featuring her new single "GTFO," the classic "Emotions" and a medley of "Honey," "Shake It Off," "Obsessed" and "#Beautiful."

11:35 p.m.: Following an outfit change for "GTFO," Carey is now in a new sparkly mini-dress topped with a dramatic sequin robe. The real treat comes with the last two songs: "Always Be My Baby" and "We Belong Together," which might as well be her Vegas theme song, since Mimi and Sin City are a perfect match.

11:59 p.m.: Kygo, the final performer of the night, starts his string of guests with Justin Jesso for "Stargazing."

12:05 a.m.: Next up is Sandro Cavazza for a yet-unreleased song with the chorus "I hope you'll be happy now."

12:08 a.m.: Miguel wins the set, making the concertgoers still in their seats very happy they stayed for his Kygo collab "Remind Me to Forget."

12:13 a.m.: The final song of the night is "Firestone, "and the final guest is singer Conrad Sewell.