"So You Think You Can Dance": Top 20 perform live

(CBS News) After weeks of auditions, callbacks in Las Vegas and a special episode revealing this year's cast, the Top 20 dancers  paired up Wednesday and performed for the judges' praise and America's votes on "So You Think You Can Dance."

The night started off with an office-themed group number, before the pairs and their dancing styles for the night were revealed.

Pictures: "So You Think You Can Dance" Season 9

Dancing first were Whitney Carson and Cheon Wespi-Tschopp, who danced a samba choreographed by "Dancing with the Stars" pro Louis Van Amstel. Carson, a ballroom dancer, was in her element and the judges knew it - Mary Murphy put her on the Hot Tamale Train. Wespi-Tschopp, a ballet dancer, looked strong and confident but was criticized for being too stiff.

Next up was Tiffany Maher and George Lawrence II, who performed a Sonya Tayeh contemporary routine. Murphy said they surrendered to the choreography, while guest judge Kenny Ortega (who choreographed "Dirty Dancing") said it was exquisite to watch.

Janaya French and Brandon Mitchell went third, dancing a NappyTabs hip-hop routine about an alcoholic who has to choose between love and his addiction. Nigel Lythgoe said French needs to get "get down and dirty a little bit more," for hip-hop and that they both need to do more if they want to stay in the competition.

Alexa Anderson was paired with Daniel Baker for a red-clad jazz routine full of lifts and turns by Sean Cheeseman. Lythgoe said the choreography was difficult, but it was hard to make a connection with the judges and audience. Ortega agreed, telling them he was impressed "with the exercise," but not with the performance.

Another ballroom number came next - a Jason Gilkison-choreographed, flowy Viennese waltz danced by Amber Jackson and Nick Bloxom-Carter. Jackson, a contemporary dancer, got flak from Murphy for not knowing how to move in ballroom heels, and Nigel told Bloxom-Carter his face was "anxious."

Contemporary dancers Amelia Lowe and Will Thomas became cats for another NappyTabs routine. Lythgoe said the routine wasn't really hip-hop, but he likes these two paired together. Murphy called the dance "purrrrfect."

Belly dancer Janielle Isis and Dareian Kujawa were paired together for an African jazz routine by Cheeseman. Lythgoe called them exciting to watch, and said he thinks they'll do well on the show. Kujawa was also praised for his work during the group number at the beginning of the episode.

Eliana Gerard and Cyrus "Glitch" Spencer were given a Broadway routine from Tyce Diorio. The "Hairspray" number was out of both of their elements - she's a ballet dancer; he's a robot/animator. Ortega said he could see it as a whole number on Broadway. Murphy said the routine brought the house down, while Lythgoe said Spencer is good at what he does, but is not a great dancer yet. He also said Gerard set the bar for the girls this season.

Audrey Case and Matthew Kazmierczak danced a Travis Wall contemporary number set on the Titantic to "Unchained Melody." A lot of the movement - including one very dramatic lift - took place on and around a chaise lounge. The judges gave it a standing ovation, with Lythgoe calling it his favorite routine of the night. Murphy said it was breathtaking, and Ortega told them it was "expertly choreographed and beautifully danced."

Last to go were Lindsay Arnold and Kole Horibe, who danced a paso doble choreographed by Jason Gilkinson. The intense, smoldering piece - which highlighted her sexiness and his martial-arts agility - brought the house down. Ortega said it was two of the best performances he's ever seen on the show. Murphy told them it was so good it made her angry, and Lythoe said it was the best paso doble he's ever seen a male dancer do on the show.

After America votes (for individual dancers, not pairs), three males and three females will be sent to the bottom three, and the judges will ultimately decide who goes home. Next week, when the show returns, two women and two men will be sent packing. This year, one male and one female dancer will be crowned winners. 

Tell us: Who do you think will go home next week on "So You Think You Can Dance"?