It's been around for only a couple of years, but the iHeartRadio Music Festival has already acquired a reputation for attracting big-name talent. This year's lineup is no exception.

The third-annual iHeartRadio fest, scheduled for Sept. 20 and 21 at the MGM Grand in Las Vegas, will play host to more than a dozen bestselling artists, and although the acts on tap for this year reflect the festival's overall pop-friendly focus, the organizers also managed to land a pair of classic-rock legends: Elton John, who will be promoting his upcoming album, 'The Diving Board,' and Queen, who will perform with Adam Lambert on vocals.

Of the two acts, Queen is arguably the bigger coup. Following the departure of Paul Rodgers, who handled vocal duties for the band between 2004 and 2009, guitarist Brian May and drummer Roger Taylor have scheduled dates sparingly over the past several years, performing mostly at special events like charity gigs or the closing ceremonies of the 2012 Olympics.

It's worth noting that one of Queen's recent shows with Lambert was a joint concert with John, and given iHeartRadio Music Festival's history of encouraging collaboration between artists, it would seem more than a little likely that we could be seeing these two acts onstage together.