According to fox this is what the show is all about.
The summer hit SO YOU THINK YOU CAN DANCE, hosted by Cat Deeley, keeps viewers moving to a different beat as dancers skilled in everything from the 'street' styles of Hip-Hop, Krumping and Popping to Ballroom's Salsa, Quickstep and Jive compete to be named the nation's favorite.

In its third season, SO YOU THINK YOU CAN DANCE finished Summer 2007 as the No. 1 show in its time period among key demographics. The Season Three champion, Sabra Johnson, was voted America's Favorite Dancer and waltzed off with the cash prize of $250,000. Following the season finale, the Top 10 dancers embarked on a cross-country, 50-city performance tour.

In Season Four, producers again will travel across the country in search of dancers who represent the rhythm of America. Those who spark the judges' interest during auditions will be invited to call-backs, where they will work with top choreographers. During the call-back week, the judges choose the Top 20 dancers who will continue in the competition.

In the performance round, the 20 finalists dance for America's votes, and each week the six contestants comprising the bottom three couples are given a chance to perform solo routines to encourage viewers to keep them on the show. Then the judges decide which dancers stay in the competition and which two are eliminated.

Once the series is down to the Top 10 finalists, it's solely up to America to decide who remains in the competition. Following the performance shows, viewers can vote for their favorite couples. The live results shows reveal who keeps dancing and who goes home.

Emmy-nominated SO YOU THINK YOU CAN DANCE was created by Simon Fuller and Nigel Lythgoe and comes from 19 Entertainment Ltd. and dick clark productions. It is executive-produced by Simon Fuller, Nigel Lythgoe and Barry Adelman.