Jimmy Fallon opened up his tenure as host of the 'Tonight Show' in style last night. Fallon created a very funny dance piece with a little help from his first guest, Will Smith.

Will Smith helped Jimmy Fallon take a trip down memory lane. They created a whole dance routine based around the history of hip hop music. It comes to a screeching halt once Fallon decides to start "Twerking." It's all fun and games until someone sticks their butt out!