ET'S MUSIC TOUR BLOWOUT! Only ET takes you exclusively behind the scenes with Lady Gaga for the opening night of her Las Vegas residency.

Plus, why is Celine Dion saying goodbye to Sin City? Then, Inside the record breaking return of Britney Spears and what she's only telling ET!

And, new SPICE Girls reunion secrets! Plus, Kelly Clarkson and Pink talk touring with their kids.

Entertainment Begins and Ends with ET!