via Pete Wentz/Instagram

Elton John. Courtney Love. 2 Chainz... and now Ryan Adams: Fall Out Boy's comeback run is lassoing in yet another unexpected collaborator, this time with a pair of studio sessions with the prolific country-rock singer-songwriter. The aforementioned artists all appeared on the Chicago pop-punk band's reunion LP, Save Rock and Roll, but the quartet are working on an all-new punk project with Adams. Rawk!

Bassist Pete Wentz, who first revealed the project via an Instagram pic taken inside Adams' Los Angeles studio, spoke with Rolling Stone about the impromptu sessions. He said after meeting for dinner at L.A.'s M Café, the band hit Adams' Pax Am studios to track "eight or nine" songs over two marathon nights. 

"It was punk rock – the stuff that makes you want to kick the sh-t out of your bedroom at your parents' house," Wentz said. "It's impossible to deny the spirit of what was happening there." Adams and Fall Out Boy were introduced by mutual friend and collaborator Butch Walker. 

"It was wild," said Wentz. "It was like hanging out with your older brother that got you into punk rock. Except he gets all the jokes and he's not like, 'Here's these sh-tty kids' or whatever. So that was cool." 

Wentz added, "It was set up like how we used to practice in [guitarist] Joe [Trohman's] parents' attic – in the corner of the room. We played loud and Patrick was singing live vocals, so it was very raw." 

Wentz said that new track "Keeping Up Disappearances" was a favorite from the session, which stretched until 2 A.M.

"I don't know if it's a thought or a title or what," he said. "It was cool because it took you back to when we started the band. There were ideas, yelling, laughing and a lot of jokes, just for the heck of it. It was really good for the spirit of Fall Out Boy. We just haven't ever done that."

No word yet on releasing the tracks, but Wentz said, "I would hope that somewhere in some universe you could put out a seven-inch and kids still care. I think that there's a formula for something like that to happen with Fall Out Boy. I think there's a side of our band in our fans that would appreciate some of the noise that Ryan comes up with, and it would be great for the fans to be able to hear that – hear sort of the raw energy that happens from sessions like that."