"Say weed!," urged Miley Cyrus before snapping the above pic with iHeartMedia's John Sykes, Tom Poleman and Marissa Morris during this weekend's iHeartRadio Music Festival in Las Vegas. Moments after striking a pose, the group assumed very different positions, as Cyrus led them in a pre-show yoga sesh.

The sixth annual fest was hosted by Ryan Seacrest and took place at the T-Mobile Arena. U2, Drake, Sia, twenty one pilots, Sam Hunt, Billy Idol and OneRepublic performed on Friday, while Sting, Usher, Britney Spears, Pitbull, Ariana Grande, Florida Georgia Line, Zedd, Tears for Fears and Cage the Elephant took the stage on Saturday.

But, that's not all. On Saturday afternoon, another party was raging on at the Las Vegas Village across from the Luxor Hotel and Casino, where Sam Hunt, Panic! At The Disco, Alessia Cara, Troye Sivan, Hailee Steinfeld, Good Charlotte, Jeremih, Lissie, Cold War Kids, Daya, Cage The Elephant, The Chainsmokers, Bryson Tiller, DNCE and Tinashe all performed.

Weekend highlights included an array of surprise collaborations. For one, Cyrus joined Idol to blow the lid of the arena with a smoking rendition of "Rebel Yell," Florida Georgia Line brought the nostalgia when they welcomed the Backstreet Boys on stage for "Everybody," and Zedd invited a handful of guests out, including MAGIC!, Aloe Blacc and Hailee Steinfeld, before playing drums for Ariana Grande. And Usher reunited with Lil Jon and Ludacris for "Lovers & Friends" and "Yeah!"

The weekend's list of celebrity guests and presenters included Sean Penn, John Stamos, Taylor Lautner, David Spade, Lea Michele, Idina Menzel, Kathy Griffin, Hailee Steinfeld, Wilmer Valderrama, Jussie Smollett, Laurie Hernandez, Sabrina Carpenter, The Bachelor's Ben Higgins and Lauren Bushnell, The Bachelorette's Joelle Fletcher and Jordan Rodgers, and more, plus iHeartRadio’s on-air talent, Ryan Seacrest, Big Boy, Bobby Bones, Elvis Duran, The Breakfast Club and Woody.

We'd also like to draw attention to U2's spectacular opening moment. During "Desire," the band dropped $10,000,000,000 (ten-trillion) dollar bills from the ceiling. Said bills had Donald Trump's face printed on them, alongside the phrase “Make America Hate Again.” Well done, boys.

And all of this was not just done in the spirit of fun and games, mind you. In the past five years, the event has helped raise $1.7m for myriad charities, including the American Association of Cancer Research, Lupus Research Alliance, Ryan Seacrest Foundation, CureDuchenne, The Grammy Foundation, ALS/Augie’s Quest and The American Red Cross.

By the way, if you decided to enjoy the past weekend from the comfort of your own air-conditioned living room, fear not. An exclusive two-night special will broadcast via The CW on 10/6 and 10/7 from 8-10pm EST/PST.

And now, photos:

Scooter Braun, Ariana Grande and KIIS’ Beata

Poleman, Sia and Sykes

Warner Bros.' Peter Gray, Bebe Rexha and EVP Commerce, Digital Marketing and
Strategy Larry Mattera

Bob Pittman, Sykes, Poleman (Photo by Steve Prue)

Poleman, Sting, Sykes (Photo by Steve Prue)