This was originally published in the July 8, 2010 issue of Rolling Stone. In her dressing room in Nottingham, England, Lady Gaga dances to a Billy Joel album, which is spinning on the small record player that’s become a backstage fixture. She hops into a chair in front of her makeup mirror and plays a rough cut of the video for her latest single, “Alejandro,” on mute on her MacBook Pro. Considerin