'Dancing With the Stars' Premieres Tonight

The wait is over: "Dancing With the Stars" will premiere tonight and "Good Morning America" went behind the scenes to see who will have some rhythm and who will have lead feet.

The contestants all had different motivations for competing on the show.

"It looked like you guys were having so much fun," boxer Leila Ali said to former "DWTS" contestant Stacy Keibler.

"Well I'm a huge fan of the show so I sat back and watched it like, 'Oh you can do better than that. Lift that leg a little higher. I could do that," supermodel Paulina Porizkova told "GMA."

Actor John Ratzenberger, who played mailman Cliff on "Cheers," said he didn't realize how popular "Dancing With the Stars" was until he got involved.

"I didn't realize what a big show it was, until ... a lady at the paint store came up to me and started giving me tips," Ratzenberger said. "When I was on 'Cheers,' no one ever came up to me and told me how to deliver the mail."

"Ballroom dancing is great exercise, especially when you have a little lady hitting you on the back of the leg saying, 'quick and slow and quick and slow,'" Billy Ray Cyrus said.

Cast member Heather Mills shared her feelings about the competition last week on "Good Morning America."

"You can do anything with an artificial leg," Mills said. "There are people who run races with just one leg."

But many of these competitive contestants aren't used to suffering defeats all that often.

"I'm definitely aware that this is a competition at all times, so I'm not one of those people who are like, 'Oh I'm just here to have fun and stay on as long as I can,'" Ali said. "No, I'm like, 'I'm here to stay on to the end and win.' ... My Dad isn't good at dancing. ... I have to represent for the whole family when it comes to dance."

Olympic gold medalist Apolo Anton Ohno said his sport will help him in the competition.

"I feel like I have rhythm since it takes some of that in skating," he said.

So have these novices learned to turn the heat up in their dancing styles?

"[I] normally have my hair French-braided, grease on, no makeup and then I'm in public getting photographs taken," Ali said. "So for me to be able to dress up and get all glammed up ... I never have the opportunity to do that."

"People say that at the beginning of the show the guys say, 'Oh I'm not gonna wear that,' but by the end they're wearing something crazy," Ohno said. "You know I wear spandex everyday, but I mean, I don't wear it to the mall. You know I'm not that guy."

There are plenty of pitfalls to being a novice dancer -- especially the "falls" part.

"I'm trying to survive the steps. I thought at first I'd master the steps, then I'd act with the steps," Porizkova said. "But now I'm like, 'Just try to get the steps right and fall down as little as possible."

"You know I'm not going to try to pretend to be Fred Astaire ... I never will be," Cyrus said. "I'm Billy Ray Cyrus from Flatwoods, Ky., and I think this is where the barroom meets the ballroom. I'm the barroom."