Adam Lambert isn't the only singer with a spot behind the microphone for Queen.

Billboard reports that Nate Ruess, lead vocalist for fun., has been seen rehearsing with Queen in advance of the iHeartRadio Festival, set to kick off Sept. 20 in Las Vegas. According to the trade's sources, Ruess handled vocals on 'Somebody to Love' and 'Fat Bottomed Girls.'

For veteran fun. fans, Ruess' Queen hookup is a long time coming; the band's first album, 'Aim & Ignite,' boasted a number of intricate, heavily Queen-influenced arrangements (and an assist from Roger Joseph Manning, Jr. of Jellyfish, a band that leaned heavily on Queen's musical blueprint in the early-'90s). Although fun.'s most recent record, their breakthrough effort 'Some Nights,' had more of a modern pop sheen, the thought of future collaborations between the two camps is certainly an intriguing one.

And as it happens, it looks like some new music -- or "new" music -- from Queen is becoming more of a possibility. Guitarist Brian May has publicly mulled the idea of cobbling together some odds and sods from the band's vaults, saying, "We thought we'd exhausted everything that was around and could be worked on, but since then a number of things have come to light from various sources that we'd just plain forgotten about...Just a couple of weeks ago, we thought: Maybe we shouldn't be just working on bits and pieces? Maybe we should be heading towards an album? It just might be."