(Cover) - EN Showbiz - Demi Lovato will "shock" with her upcoming record, according to collaborator Ryan Tedder.

The singer-and-actress has famously had a difficult time recently, entering a treatment facility in Chicago to get help for "emotional and physical issues" last year.

The 18-year-old songstress is now working on her third studio album, Unbroken, after starting it in July 2010 prior to receiving treatment.

OneRepublic's Ryan collaborated with Demi on Who's That? - a song he penned and also produced for the former Disney star.

He says that the album has taken a U-turn away from the very personal single Skyscraper, which Demi released last month.

"I think everybody wanted to hear her talk about that, and this is basically flipping it 180, saying, 'Oh, by the way, I'm still also just young and want to have fun.' There's even like a little rap feature on it

"No, she doesn't rap on it," he laughed in an interview with E! Online. "I'm going to keep that [person] a secret. But she's got a couple features on this album, one in particular that is going to shock everybody. I was like, 'How did you get this person? They're impossible to get and you got them!'"

Ryan also gushed about Demi's talent. The Grammy-nominated singer-songwriter was initially shocked to hear how powerful her voice was.

"Demi blew me out of the water vocally!" he said. "I had no idea how good her voice is. She's one of the best singers I've ever worked with. Literally, that good... I mean, she's a Kelly Clarkson-level vocalist. And Kelly has a set of pipes." (C) Cover Media