When an artist wants to get the party started, who better to call than Timbaland? The producing powerhouse, who helped shape recent smash hits by Justin Timberlake and Nelly Furtado, toiled on half of the tracks on Ashlee's upcoming release, tentatively titled Bittersweet World. He lent his expertise on "Out of My Head (Ay Ya Ya)," "Murder," "Can't Have It All," and "Rulebreaker" while the rest were guided by the Neptunes' Chad Hugo and critically acclaimed Ethiopian synth-hop savant Kenna.

Ashlee explains, "The room was so blessed with talent. I was very lucky to work with people who are at the top of their game". She quickly learned that hip-hop heroes move at a different pace than pop stars. "I have never worked until 4 a.m. before. I wouldn't go in until late in the afternoon and then we'd work until the wee hours of morning if we had it in us. I started bringing a blanket with me. I got a little loopy and punchy late at night, which affected some of the songs. It was so cool for me to be able to step outside of the way I had always done it before and try new things."

More help came courtesy of Travis McCoy, the frontman of Gym Class Heroes, who raps on "Murder." The two run in similar circles and she's a big fan of his MC skills. "The band's so huge now and he's so busy that he had to send me his part from overseas. I was happy he made the time because he just gets me and it completed the song." Don't let the somber title fool you. The 23-year-old has not gone gangsta. "No, it isn't serious, based on a true story or a threat," she explains laughing. "It's a metaphor about a girl who can get away with murder because of who she is".

She also touches on the cattiness of girls on "Hot Stuff," a coquette-ish sassiness on "Boys" and how fun it is to sometimes do the wrong thing on "Rulebreaker." She was trying "to capture that badass feeling you get sometimes after watching a movie like True Romance. You think you can take on the world and you want to color outside the lines and get a tattoo or mouth off to someone way bigger than you."

Her personal favorite is the slow jam "Never Dream Alone," because "it is a sweet emotional song that has been stripped down to piano, strings and vocals."

She also wrote or co-wrote every track and the final product is a mix of ballads, radio-friendly anthems and dance floor ditties per usual. "I never want to be handed a song to sing. I don't work that way. This is my art and it's personal. If someone else writes the song without my input, it doesn't feel honest."

Ashlee continues to pull from her own experiences or things she witnesses those around her weathering for lyrical subject matter, but says most verses aren't as literal as they have been on past singles. "Lyrically this album is a bit more abstract and quirky than my past stuff was although I'm still singing about things I've gone through or friends went through. The topics are diverse and universal so I think people will be able to fit the songs into their own lives too."

Her favorite collaborative partner is still her childhood friend/band guitarist Ray Brady. "I trust him completely. He plays on every track and is my sounding board. We sit in a corner writing and working out alternative versions to play live. He's always introducing me to new music that helps me evolve as an artist."

One such act Brady brought into her life was Missing Persons and Ashlee's never been the same. "I love those strong women from the late '70s and '80s. They are strong and vulnerable simultaneously, yet they still make you want to dance. Women like Chrissie Hynde, Debbie Harry and Pat Benatar have really inspired my music for the last two years and you will definitely be reminded of that era when you listen to the new album."

The veteran of two sold-out tours can't wait to get back on the road again. "That's my favorite part of the job. I love playing live and seeing up close and personal how your music affects other people. I love seeing the reactions on fan faces and hearing them sing along. I want them to go on this journey with me. When it comes time to tour, I'll still experiment with different or acoustic versions of songs. I hate when I go to concerts and it's like I could've stayed home and listened to the CD and gotten the same experience. I wouldn't feel right doing that to people who shell out money to see me."

Now with accolades such as Billboard Artist of the Year (2004), two Teen Choice Awards, countless magazine covers and appearances and performances on shows as varied as MTV Video Music Awards, Teen Choice Awards, and the American Music Awards to her credit, and an exciting new album to look forward to, no doubt the future will continue to be bright for Ashlee Simpson. "The most important thing is that this is something I really enjoy doing," she says. "I love creating and participating in projects people can connect to."