As Britney Spears prepares to launch her Onyx Hotel Tour, a few more details have leaked out, thanks to a few well-placed cameras on Monday at San Diego's final full rehearsal, which she opened up to a few fans and contest winners.

The singer's set list will mostly contain songs from In the Zone, with only a handful of older songs making the cut. Among those will be "Boys," "Overprotected" and a jazzy/bluesy medley mix up of "Oops! ... I Did It Again" and "... Baby One More Time" that will have a cabaret feel.

Adding to the theater atmosphere will be a rotund MC, who'll welcome fans to the Onyx Hotel. The stage production takes a few cues from Broadway musicals based on events in the 1930s (see [article id="1485366"]"Britney Spears Releasing Diddy-Produced Song On DVD"[/article]) but modernizes the look with crashing chandeliers and a few explosions. As for Spears, she and her dancers are attired in much more modern dress, including a practically sewn-on rubberlike outfit that covers just about everything except for a large open area from her bust to her neck. Her dancers opt for more comfortable looking but seemingly exotic wear, with touches of kimono and camouflage clothing. ([article id="1485495"]Click for behind-the-scenes photos of Britney's tour rehearsal.[/article])

The "more adult" hotel theme, Spears said in a videotaped interview sent out by her label, was inspired by having to travel so much, whereas adding the onyx stone to the concept helps bring a spark of magic.

"I would love my audience to walk out of the auditorium feeling like they had the most magical experience of their life," she said. "The onyx stone is kind of symbolic of what guides me in my life, like there's a bigger picture in everything, and there's something that guides you where you need to go, from point A to point B."

The new songs are taking center stage, she said, "because you need a new craft, something new to express and give to people, and it makes it exciting for me." Of the new material, current single "Toxic" and next single "Everytime" are the songs she's looking most forward to performing.

"I really think I'm talking to everyone when I perform 'Everytime,' " she said of the ballad. "It's about heartbreak, it's about your first love, your first true love. That's something all people can relate to, because you all have that first love that you think you're going to be with the rest of your life."

Spears said she's "getting jitters" just thinking about having to perform the songs outside of rehearsal, though she noted she works "very well under pressure." She said she's looking forward to playing venues in smaller markets "because they're so enthused for you there," and it helps make her feel better about the otherwise high-pressure experience.

"When things get crazy and chaotic, I just go inside myself, just express myself and do my thing," she said. "The day I'm going to perform, oh my goodness, I'm probably going to wake up and be a nervous wreck. I'll go to the venue, just kind of meditate, stay in my room, talk to the dancers, work out everything, and just go out there and do it, man, just do it."

Spears revealed that for her stop in Miami, which will air on Showtime, there'll be two special guests "who are going to heighten it and make it a little bit more exciting." The concert special airs March 28 at 9 p.m., live in the Eastern time zone, but tape delayed elsewhere.

"I think it's good for your soul to travel," Spears said of the trek. "It makes me feel free, very free, very creative. I love going home but I can't stay there too long. I love what I do too much."

The tour kicks off Tuesday (March 2) in San Diego and hits 25 North American cities before wrapping up April 12 in New York (see [article id="1480899"]"Britney Spears Lines Up Tour For In The Zone"[/article]).