Transcript for Former Pros Return for Big Reunion Dance on 'DWTS'
stars," the nakeded version. This is what our studio looks like without the lights, the costumes, the camera, the action. Reporter: The ballroom is asleep. About to come alive for one of the biggest dance numbers in the show's history. Everybody is back. It is going to be one of the biggest pro numbers we have ever had. Celebrities, the show will be amazing. Things never get boring around here. We have light-up bracelets. Reporter: Pro dancers from the first 15 vns here, like one big family reunion. The dance floor misses you. I'm glad you're back. And I'm back, too. ♪ Reporter: The lights, cameras, music, and notice the colors slowly broigten adds monday approaches. 29 dancers and over 100 costumes. A record for tonight's show. While the celebrities are dancing, the other celebrities hang out on this balcony supporting one another. Yeah, baby, go jacoby! Every sunday, we have camera brocking. We work out the choreography, the first time we do it on stage with the lightses, the glitz, the glamour. I miss the camaraderie with the guys and the crew. They tell us what looks good and doesn't. You like that one? Oh, I loved it. There you go. What are the things you miss about camera brocking? Nothing. Is there where the choreography starts working itself out? Or something gets killed. A hot pink chick looking at us. A sun burn. We're blinded right now. Wow, look at you, girl. And you got the rhinestones underneath. Reporter: A dance tonight that will come out of the sky. One more time. Can you do it again? No, thank you.
This transcript has been automatically generated and may not be 100% accurate.