Twenty-one-year-old Jessica Simpson [ tickets ] has a long summer ahead of her. Starting on Aug. 7 in Corpus Christi, Texas, Simpson will headline the Dreamchasers tour, a bill that features Eden's Crush, Youngstown, Toya and Plus One. A full itinerary for the tour will be available soon.

She's also picking up 12 dates on the inaugural "Total Request Live" tour, featuring fellow Texans Destiny's Child.

In a dance rehearsal studio in North Hollywood, Simpson talked about her new album, "Irresistible," and her upcoming tours. Wearing a white T-shirt and shorts, and with her long blonde hair tumbling out from underneath a floppy camouflage hat, Simpson sat at a glass table in the dressing room while her mom leaned over the couch, occasionally mouthing answers over the reporter's shoulder when her daughter forgot a detail or left something out.

LiveDaily: I wanted to find out about the Dreamchasers tour. You're going out with Eden's Crush, Youngstown, Toya and Plus One. Did you pick the lineup?

Jessica Simpson: I didn�t pick the lineup. My father�s my manager, so I left picking and choosing of the opening acts up to him. I approved, like, "Yeah, nah, yeah."

Tell me a little bit about the "Extreme Mobile Unit" you�re going to have out on tour with you.

It�s going to be kind of like a circus-vibe, like a circus tent-type thing. But it seats, like, 9,000 people, and it�s cool because I�m bringing the tour to the city. It�s not like when you go to a show, you normally go to the same places to see it. And I think this will be really fresh and new and fun for everybody.

Where will you set up?

I think we�re setting up adjacent to the mall. It�s not a mall tour. It�s not at the mall. But it�s right next to it. We�re going to use the parking area.

What kinds of things is it going to have?

There�s a rock-climbing wall, there�s a motorcycle--we�re having a traveling motorcycle person, I don�t know what you call them. Bungee-jumping. There�ll be lots of music throughout the day. Interactive computers. It will be an all-day event.

In terms of getting ready for the new tour, how many different dances do you have to learn?

Getting ready for the tour is a hard thing, because there�s so many details involved. As far as choreography goes, yeah, you have to learn exactly what place to go on this word, exactly what place to go [on another] word. There�s a lot of memorization.

How many dancers do you have?

There�s six.

How long have you been rehearsing?

On and off. Whenever we get an off-day, that�s what we have to do. By the time the tour starts, we�ll have put in about three weeks of rehearsal.

In terms of the songs you�re using, are you going to do medleys, or full songs?

There�s an acoustic set that�s a medley of some of my favorite songs: "Water Runs Dry" by Boyz II Men, "I Believe I Can Fly" by R. Kelly, and "When Will I See You Again" by Babyface. So it�s going to be, like, a medley of not even my material. Which is going to be exciting.

Are you bringing out a band?

A full band. Two guitars, one being bass, one being lead. Two keys, drummer, back-up singers. That�s it.

And you�re going to be part of the "TRL" tour also?

Yeah, I�m doing 12 shows.

How has your vocal style developed since the last record?

My new record is something completely new and fresh for me, and it was really exciting to be able to grow as an artist in the studio, and it really has a lot of confidence behind it. Everything grew up, from my vocals to my image to everything--it�s all kind of grown up with me. I still have fun pop songs and I still have some great ballads and a duet with Marc Anthony. Lots of great stuff.

Tell me about the duet you did with Marc Anthony on the song "There You Were." How did you get hooked up with him?

Marc and I are friends, but we were actually singing for President Clinton, for the "Christmas in Washington" thing and Marc asked me to do a duet with him for his record. So our song, "There You Were," is going to be on his album, too.

What was it like working with him?

It was great to work with Marc, because he�s really passionate about everything that he does and he�s just a phenomenal singer. It was just great to learn from him and sit back and watch how he works in the studio. He�s completely professional about everything he does, so I got a lot of tips.

What kind of things?

I think the best thing about Marc is that he sings from his soul, he sings from his heart. That�s what is most important. He really takes a song and looks at the lyrics and tries to relate it with his own life.

Was that song written with him in mind?

I think Sam [Watters] and Louis [Biancaniello], who wrote the song, were planning on using it for that, yeah, it was written for Marc and I. We said we wanted to do a duet, and then we went out and found the best song.

How do you pick the songs that you use? What�s the criteria for you, what do you look for?

Well, on this album, I really trusted Tommy Mottola. He basically hand-chose, with me, every single song. It was a lot easier for this record to choose the songs than the last record, because you have more of an opportunity to work with the best. If I don�t like a song and he does, he has me sit and live with it. One of �em I didn�t like, it ended up being my next single. You really have to trust people the people around you.

What song was that?

"A Little Bit."

I thought that was part of a group of three songs that couldn�t have been on your previous record, songs that have a little more attitude. Is it exciting for you to try something like that?

Yeah, absolutely. Because when you do the same thing every day, the same music every day, it can get really monotonous. So it�s good to freshen up with all different flavors.

Do you feel like there�s a specific song that couldn�t have been on your last record, for instance? Do you feel like there�s some songs that, because you�ve had that growth, you�re able to have on this record?

Yeah, there�s some stuff that�s a little more R&B that wouldn�t have fit with the last record, but it fits with this record because it�s a great blend of pop, R&B and pop/R&B. So my R&B stuff blends more with this record than my last record.

I read an interview with you where you were saying that you feel like a lot of pop has been done. What do you try to do differently to keep it interesting?

I just give it variety. I think there�s a lot of songs out there that are talentless. You know what I mean? They�re just songs you hear on the radio because that�s what the radio is playing. I think it�s important when you choose songs for your album to know that, and to want to be respected for the material you choose.

I�ve read that you�re going to be in a movie in January or around then.

Our fingers are crossed that I get January off so I can shoot a movie.

What movie is it?

It�s not out yet on press. I can�t talk about it.

You did a version of "His Eye Is on the Sparrow" for this album. That�s a song that you used to sing in church. Did you change the arrangement compared to how you might have sung it in church?

Yeah, absolutely. "His Eye Is on the Sparrow" is one of my favorite songs, one of my favorite gospel songs in the world, and it�s a very special song for me. So we basically took it and made it our own. I worked with the producer and had a lot of input on it.

What kind of things did you change, compared to if someone heard it in a church?

If someone heard it in a church, it would be slow, all the way. We sped it up. It starts off slow and then it gets fast and then it gets faster and then it gets faster. It�s like down-home gospel.

There�s a choir on there. Is that your church choir?

No, those are just studio choir--well, they�re not just studio, but they�re Mariah Carey�s back-up singers, some of the most amazing singers in the world.