RedOne the producer behind Lady Gaga’s Bad Romance reveals how the song was created, from a simple bus demo with headphones to a worldwide anthem performed by thousands of fans.

But what if the story didn’t end there? In between legs of her “Mayhem Ball” tour, Gaga debuted “Apple Music Live: Lady Gaga Mayhem Requiem,” live directed by Micah Bickham, at Los Angeles’ Wiltern in ...