Britney Spears' 'Hold It Against Me' Is 'Tip Of The Iceberg,' Songwriter Claude Kelly Says

'It sounds grimier,' Kelly says of Spears' forthcoming Femme Fatale album.

With only days until [artist id="501686"]Britney Spears[/artist] releases the music video for [article id="1657987"]Femme Fatale's first single, "Hold It Against Me,"[/article] more details about the album itself are starting to emerge. Songwriter [article id="1656529"]Claude Kelly, who worked with Spears[/article] on the album, explains that the lead single is only a taste of what fans will hear on the album, which is being produced by Dr. Luke and Max Martin.

"I would say ['Hold It Against Me' is] the tip of the iceberg because that's the very beginning of a whole album," he explained to the Orlando Sentinel, adding that this album will be "darker" and "edgier" than 2008's Circus, though it will "still [have] fun pop records."

The finishing touches on the March 29 release are currently taking place, and that means that even Kelly is in the dark about which of his songs made the final cut. "[Luke and Martin are] in charge, but I've written a couple songs," he explained. "I'm not even sure myself what made the cut. I know there's something workable in there, but I worked on her last album as well, so it's kind of a continuation of that. But it's a little edgier this time, darker. It sounds grimier and dub step and danceable."

Kelly enjoys working with Spears because she is up for anything in the studio. "For me, I get inspired by the artist that I'm working with. With Britney, she's really not afraid to try anything," he explained. "So it allows you to be more creative and say sexier things, say more mysterious things with her. It's kind of all things go."

Don't miss Britney Spears' "Hold It Against Me" video premiere Thursday, February 17, at 9:56 p.m. ET on MTV and MTV.com, followed by a live discussion on MTV.com at 11 p.m. about the new clip and what's next for the pop star!