Sia Performs 'The Greatest' Live at Apple Keynote

Sia takes to the stage at the Apple Keynote presentation on Wednesday (September 7) at the Bill Graham Civic Auditorium in San Francisco, Calif.

The 40-year-old singer was joined on stage by 13-year-old dancer Maddie Ziegler, who has performed in several of her music videos, including her latest single “The Greatest.”

PHOTOS: Check out the latest pics of Sia

During her performance, Sia debuted “The Greatest” live for the first time in addition to singing her hit “Chandelier.”

Check out the entire performance below…