LIVE Fun. to Perform With Queen at iHeartRadio Music Festival (Updated)

fun. performs during the Inaugural Ball at the Walter E. Washington Convention Center in Washington, D.C.

UPDATED: Billboard has learned that Ruess' entire band, Fun., will be performing with Queen.

Queen will team up with another powerhouse singer at the iHeartRadio Music Festival this weekend. Nate Ruess of Fun. is set to take the stage with the legendary British rock group at the MGM Grand Garden Arena in Las Vegas, a source confirms to Billboard.

Ruess and the band -- led by Brian May and Roger Taylor, along with guest frontman Adam Lambert -- were spotted rehearsing "Somebody to Love" and "Fat Bottomed Girls" on Tuesday (Sept. 17), however it's unclear how many songs they'll perform together.

Fun. Covers Queen's 'Radio Gaga' in 2010

Queen and Lambert are on the bill for Friday night, as is Ruess' Fun., whose hits include "We Are Young," "Some Nights" and "Carry On."

Friday night will also see performances from Katy Perry, Elton John, Keith Urban, J. Cole, Muse, Tiesto, Chris Brown and Benny Benassi. Saturday artists include Paul McCartney, Justin Timberlake, Drake, Miley Cyrus, Tim McGraw and Bruno Mars, among others.

The two-day festival will be held this Friday and Saturday at the MGM Grand Arena, with a first-time Fan Village set to run during the daytime at a 15-acre parking lot adjacent to the arena. Dubbed the iHeartRadio Music Festival Village, the space will feature performances from Miley Cyrus, Avril Lavigne, AWOLNATION, Pete Tong, Twenty One Pilots and Jason Derulo.

Billboard is heading to Vegas! Follow @JasonLipshutz and @AHampp on Twitter for updates from the MGM Grand.