As for how that all happened, Gaga has pulled back the curtain some in a new behind-the-scenes video.

"To me, this is how the magic is made," wrote Gaga about the video, which includes a cameo from Honey Balenciaga ...

It’s a melodic, slow ballad, showcasing Gaga and Mars’ vocal prowess. “Abracadabra” is not that. To understand this newest ...