There is a hidden mode you can unlock in Just Dance 3 for the PS3, Xbox 360, and Wii called Extreme Choreography Mode, which is a crazy dance routing set to Barbra Streisand.
If you’re familiar with the Konami code, then entering this code will be very familiar to you.
At the title screen, press: Up, Up, Down, Down, Left, Right, Left, Right to unlock Extreme Choreography Mode.