Jimmy Jam and Terry Lewis are hard at work on Janet Jackson's untitled next album due in 2006.

Lewis says the trio, who are celebrating 20 years of working together, have found a new, yet familiar, rhythm, reports billboard.com.

"It used to be a lot of involvement from all of us and at some point when Janet became more confident with her writing ability, she (did) the bulk of the writing," he said.

"And it's kind of back full circle. We're all kind of back in there doing it again together, which I really enjoy."

Jam said: "It's the physical nature of sitting in the same room and really hashing it out. It's like, 'You're not going to leave until we got a lyric,' so it's fun."

Some recording has taken place at Jermaine Dupri's studio. Dupri, president of Virgin Urban and Jackson's boyfriend, is also executive producer for the album.

The set will be the follow-up to 2004's "Damita Jo", which was released after Jackson's disastrous appearance during the Super Bowl show.

The set went to No. 2 on The Billboard 200 charts in the US.