"She's great," Rotem told PEOPLE at the BMI Pop Awards in Beverly Hills on Tuesday. "She's like a master at what she does. She's a lot more experienced than most people. She just has the 'it' factor that not every artist has. So it's always nice to work with her."
Although Rotem, who briefly dated Spears in 2007, would not reveal any details of the project, a Spears family source tells PEOPLE that the pop star is in the early stages of a follow-up to her last album Blackout, which was released last October.
"Britney is in the experimental stages of a new album," says the source. "She's trying to find the sound and direction she wants to go in, but nothing is set in stone just yet. She has been playing the piano a lot and just singing. She says she misses 'just singing.'"
Producer Sean Garrett was mum on specifics but says that he and Spears, 26, have "a few things in the works." At the BMI Pop Awards, Garrett told PEOPLE: "I'm just happy to see her back and recovering. She's really shaping up and getting her whole situation back together. I'm really proud and happy to see her."
A rep for Spears's record label had no comment.
Reporting by JESSICA HERNDON and JENNIFER GARCIA