Lady Gaga surprised Apple employees on Friday when she performed as the secret headlining act for their celebration of the formal opening of Apple Park.

Employees rushed to the center of Apple Headquarters campus where Gaga was performing under massive rainbow archways.

Gaga was turning out nothing but the hits for the audience, including the award-winning song “Shallow” from A Star is Born. More than just a flashy concert, Gaga showed respect to Apple founder Steve Jobs by having a moment of silence in his honor during the show.

The performance was enjoyed by everyone in attendance with Apple CEO Tim Cook thanking Lady Gaga in a tweet for helping to make their celebration “unforgettable.”