Video: Joanna Krupa's Top Secret 'Dancing with the...

The final countdown is on! Joanna Krupa and her pro partner Derek Hough have reached the final four, and ET’s at their rehearsal as they prepare to perform three dances on tonight’s "DWTS." Joanna tells ET she is in the midst of learning the "sexy, fun, cheeky" cha cha, the Viennese waltz and the salsa. "The only thing you can do and the only thing that you're in control of is just doing good dances," Hough says of the competition. "The dancing speaks for itself."