Ellen gives Gaga a hug after her performance.
An incredible performance of "Marry the Night" by Lady Gaga.
Lady Gaga opens up about a potential acting career.
Greyson Chance meets Lady Gaga backstage!
Lady Gaga celebrates three years of knowing Ellen with a special cake!
Ellen gets her Gaga going
Ellen joins Lady Gaga at the end of her world premiere performance of "Judas"
The one and only Lady Gaga sits down to talk with Ellen
Ellen and Lady Gaga show their poker faces.
Lady Gaga models her self-designed outfit.
Lady Gaga chats with Ellen
You'd never know Ellen wasn't one of Lady Gaga's dancers
Ellen tries out Lady Gaga's dance routine